Impact of Hemoglobin Level As a Continuous Variable in Calculating Prognosis in MDS: Incorporation into LSC4 and IPSS-R

INTRODUCTION: Myelodysplastic syndromes (MDS) are a group of hematopoietic stem-cell disorders, with heterogenous prognosis. The Revised International Prognostic Scoring System (IPSS-R) (Greenberg et al., Blood, 2012) is the standard prognostic scoring system that uses several clinical and cytogenetic criteria as categorical parameters to predict prognosis of patients with newly diagnosed MDS. A recent study compared the performance of IPSS-R with a panel comprised of 4 stemness-related genes: LAPTM4B, NGFRAP1, EMP1, and CPXM1 (LSC4) and showed a significant improvement of survival classification performance when focusing on gene expression panel (Wang et al., Blood Advances, 2020). Despite the recent upgrade, the performance of none of these markers is sufficient enough and there is still need for improvement. METHODS: In order to evaluate the predictive power of the LSC4 and develop novel models integrating RNA-sequencing data with clinical variables, we evaluated bone marrow samples from 56 independent MDS patients prior to any therapy. Patient samples were collected using institutional guidelines. BM mononuclear cells (MNCs) were enriched by Ficoll (GE Healthcare, Chicago, IL) protocol, following manufacture's guidance. BM CD34+ cells were enriched using magnetic cell separation (MACS) and CD34+ magnetic beads (Miltenyi Biotech, Germany). RNA from sorted BM CD34+ cells was isolated using the TRIzol RNA isolation kit (Fisher Scientific, Waltham, MA) followed by RNA-Seq library construction. FASTQ files were processed in TopHat2 using the default options. We implemented cox proportional hazard model to create the survival panel and time dependent AUCs was used in order to evaluate the performance of the model. We divided the patients into high versus low groups using optimum cutoff method and used Kaplan-Meier estimator to show the survival behavior in each group. RESULTS: In this work we first validated the LSC4 panel and compared it with the IPSS-R on our data set. Furthermore, in order to improve the classifier performance, we calculated the correlation of clinical features with survival status. We observed that Hemoglobin (Hgb), as a continuous variable, has a significant effect on predicting the overall survival and it can significantly improve the survival classification performance when combined with the IPSS-R or LSC4 scores (HR = 0.63, 95% CI 0.44 - 0.89, P <0.001 when Hgb combines with IPSS-R and HR = 0.67, 95% CI 0.48 - 0.93, P<0.001 when Hgb combines with LSC4). Our proposed models show an enhanced time AUC performance when focusing on survival status beyond 20 months of follow up compare to IPSS-R and LSC4 scores (Figure 1a). We have also observed that combining Hgb with LSC4 or IPSS-R significantly improves the confidence interval for long term survivals (Figure 1b). In fact, in these panels, unlike the IPSS-R panel, we treat Hgb as a continuous variable and we believe factorial consideration of Hgb can underestimates the true effect of this feature on survival. We also showed a distinct separation between two survival curves when we used new proposed panels amongst all patients (Figures 1c and 1d). CONCLUSIONS: In this work, while providing further validation for LSC4 model, we showed that Hemoglobin, as a continuous variable, has a significant prognostic effect when integrated with either IPSS-R or LSC4. Hereby, we observed that increasing Hgb even by a single unit can improve patient's overall survival. Figure 1 Disclosures Sasaki: Daiichi Sankyo: Consultancy; Novartis: Consultancy, Research Funding; Pfizer Japan: Consultancy; Otsuka: Honoraria. Garcia-Manero:H3 Biomedicine: Research Funding; Acceleron Pharmaceuticals: Consultancy, Honoraria; AbbVie: Honoraria, Research Funding; Novartis: Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Amphivena Therapeutics: Research Funding; Onconova: Research Funding; Helsinn Therapeutics: Consultancy, Honoraria, Research Funding; Jazz Pharmaceuticals: Consultancy; Astex Pharmaceuticals: Consultancy, Honoraria, Research Funding; Merck: Research Funding.

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Colony-Forming Unit Cell (CFU-C) Assays in Myelodysplastic Syndrome

Blood ◽

10.1182/blood.v126.23.2874.2874 ◽

2015 ◽

Vol 126 (23) ◽

pp. 2874-2874

Author(s):

Bing Li ◽

Jinqin Liu ◽

Shiqiang Qu ◽

Robert Peter Gale ◽

Ruixian Xing ◽

...

Keyword(s):

Overall Survival ◽

Scoring System ◽

Conflicts Of Interest ◽

Unit Cell ◽

International Prognostic Scoring System ◽

Hematopoietic Stem ◽

Colony Forming Unit ◽

Significant Difference

Abstract Introduction: The myelodysplastic syndromes (MDS) are a group of clonal diseases derived from hematopoietic stem cells (HSC). Colony-forming unit cell (CFU-C) assay is an effective method to study the number and the function of HSC in vitro. In this study, we focus on the characteristics and the prognostic value of CFU-C in patients with MDS. Patients and Method: CFU-C assays were performed according to the protocol of MethoCultTM H4435 Enriched (STEMCELL Technologies). A colony was defined as an aggregate of >40 cells. Clusters consisted of 4 to 40 cells. 560 consecutive newly-diagnosed, untreated subjects with MDS diagnosed from March, 2001 to April, 2013 were studied. All subjects were reclassified according to the 2008 WHO criteria. 535 subjects with evaluable cytogenetics were classified using the International Prognostic Scoring System (IPSS) and the revised International Prognostic Scoring System (IPSS-R) criteria. Follow-up data were available for 470£¨84%£©subjects. Median follow-up of survivors was 26 months (range, 1-170) months. Subjects receiving an allotransplants were censored in survival analyses. Erythroid and myeloid colonies were isolated from each subject with one cytogenetic abnormality such as del(5/5q-) or +8. Cytogenetic abnormalities of each colony were analyzed by fluorescence in situ hybridization (FISH). SPSS 17.0 software was used to make statistical analysis. Results: Frequencies of burst-forming units-erythroid (BFU-E), colony forming unit-erythroid (CFU-E) and colony forming unit-granulocytes/macrophages (CFU-G/M) were significantly lower than normals (P<0.05) (Table 1). Subjects classified as lower risk in IPSS and IPSS-R had significantly higher numbers of BFU-E and CFU-E (P<0.05) but similar numbers CFU-G/M and clusters-G/M compared with higher risk subjects (Table 2). In 11 subjects with del(-5/5q-) or +8 identified by G- and/or R-banding, both normal and abnormal CFU-Cs were identified in 8 subjects studied by FISH. A high ratio of cluster- to CFU-G/M (>0.6) was associated with poor-risk cytogenetics (Table 2) and with worse overall survival in univariable (Figure 1, P=0.001) and multivariable analyses (HR 1.748, [1.01-3.0]; P=0.046) after adjusting for IPSS. Conclusions: These data suggest abnormalities of proliferation and differentiation of erythroid and myeloid precursor cells in vitro parallel the ineffective hematopoiesis typical of MDS and may be useful in predicting outcomes of patients with MDS. Table 1. CFU-C in MDS subtypes N BFU-E CFU-E CFU-G/M N Ratio of cluster- to CFU-G/M RA 21 8 (0-44) 40 (0-134) 14 (0-127)1 6 0.25 (0.40-1.00) RT 4 18 (4-55) 75 (60-90)1 30 (18-70)1 2 2 RARS 27 12 (0-33) 35 (1-140) 12 (0-70)1 10 0.45 (0.17-0.80) RCMD 275 10 (0-80) 33 (0-178) 14 (0-100) 126 0.35 (0-0.83) RAEB1 112 10 (0-258) 32 (0-312) 14 (0-89) 53 0.47 (0-1.00) RAEB2 103 9 (0-46) 25 (0-120) 13 (0-72) 42 0.37 (0-1.00) MDS-U 15 4 (0-58) 25 (0-161) 10 (0-43) 3 2 Del(5q) 3 2 (2-4) 15 (0-20) 5 (5-41)1 1 2 1No significant difference compared with normals. 2Too few cases to analyze. Table 2. Associations between CFU-C and clinical and laboratory variables N BFU-E P CFU-E P CFU-G/M P Number Ratio of cluster- to CFU-GM P IPSS 0.064 0.006 0.361 0.089 Low 30 13 (0-44) 60 (0-169) 19 (0-45) 10 0.44 (0.24-0.70) Int-1 361 10 (0-258) 33 (0-312) 14 (0-127) 150 0.33 (0-1.00) Int-2 115 9 (0-61) 30 (0-137) 14 (0-72) 52 0.45 (0-1.00) High 29 7 (0-34) 21 (0-93) 12 (0-67) 12 0.44 (0-1.00) IPSS-R 0.003 0.003 0.125 0.209 Very low 7 16 (9-25) 30 (15-120) 18 (5-33) 2 0.29 (0.10-0.49) Low 130 14 (0-80) 42 (0-178) 17 (0-70) 48 0.31 (0-0.77) Intermediate 173 10 (0-66) 34 (0-161) 13 (0-127) 81 0.37 (0-1.00) High 139 9 (0-259) 29 (0-312) 11 (0-89) 51 0.33 (0-1.00) Very high 86 8 (0-61) 25 (0-137) 14 (0-91) 42 0.47 (0-1.00) Cytogenetics (IPSS) 0.867 0.055 0.290 0.007 Good 327 10 (0-258) 36 (0-312) 15 (0-89) 133 0.33 (0-1.00) Intermediate 133 10 (0-69) 30 (0-162) 12 (0-127) 63 0.45 (0-1.00) Poor 75 10 (0-61) 25 (0-137) 14 (0-91) 28 0.42 (0-1.00) Cytogenetics (IPSS-R) 0.990 0.090 0.676 0.022 Very good 7 11 (4-20) 48 (1-110) 14 (8-28) 2 0.49 (0.43-0.56) Good 324 10 (0-258) 35 (0-312) 15 (0-89) 132 0.33 (0-1.00) Intermediate 129 10 (0-69) 30 (0-162) 12 (0-127) 62 0.45 (0-1.00) Poor 27 10 (0-61) 35 (0-137) 16 (0-48) 8 0.36 (0.15-1.00) Very poor 48 11 (0-42) 22 (0-120) 14 (0-91) 20 0.53 (0-1.00) Figure 1. Overall survival in subjects with cluster- to CFU-G/M ratios ¡Ü or > 60%. Figure 1. Overall survival in subjects with cluster- to CFU-G/M ratios ¡Ü or > 60%. Disclosures No relevant conflicts of interest to declare.

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Clonal Suppression of TP53 Mutant MDS and Oligoblastic AML with Hypomethylating Agent Therapy Improves Overall Survival

Blood ◽

10.1182/blood-2018-99-117297 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 1817-1817 ◽

Cited By ~ 4

Author(s):

David A Sallman ◽

Najla Al Ali ◽

Seongseok Yun ◽

Eric Padron ◽

Jinming Song ◽

...

Keyword(s):

Overall Survival ◽

Research Funding ◽

Multivariable Analysis ◽

Response Rates ◽

International Prognostic Scoring System ◽

Cancer Center ◽

Cell Transplant ◽

Hematopoietic Stem ◽

Male Predominance ◽

Hypomethylating Agent

Abstract Background Hypomethylating agent (HMA) therapy represents the standard of care for patients with higher risk myelodysplastic syndromes (MDS) although only 50% of patients respond to treatment. Recent evidence from molecular profiling through next-generation sequencing (NGS) in myeloid diseases has been conflicting as to the value of somatic mutations as a biomarker for response to HMA. In particular, there have been conflicting data on response rates and outcomes in TP53 mutant (MT) MDS and acute myeloid leukemia (AML) based on azacitidine versus decitabine (Welch et al., NEJM 2016; Garcia-Manero et al., NEJM 2017). However, the TP53 mutant cohorts in these studies were small (median 23 patients, range 13-39) and heterogeneous based on treatment status (treatment naïve versus relapse/refractory). Therefore, our goal was to characterize outcomes of TP53 mutant MDS patients who received frontline HMA therapy. Patients and Methods TP53 MT MDS and oligoblastic AML (20-30% blasts) cases were retrospectively identified from the Moffitt Cancer Center MDS database. All patients had NGS of TP53 and up to 53 additional genes performed prior to the initiation of HMA. The lower limit of VAF detection was set at 5% and the minimum depth of coverage at each position was 500X. Clinical variables and outcomes of MDS patients were characterized at the time of sample procurement. Fisher's exact tests were used for comparative analyses. Kaplan-Meier curves were used to estimate overall survival (OS) and analyzed from the date of HMA initiation. Response rates and outcomes of TP53 MT patients were compared to a cohort of wildtype (WT) patients (n=63). Results From May 2013 to May 2018, a total of 71 patients with TP53 mutant MDS were identified with a median age of 68 years (39-82) and male predominance (66%). Fourteen patients (20%) had multiple mutations in TP53. Of the cohort, 82% of patients (n=58) were treated with azacitidine (88% (n=51) with AZA monotherapy; 12% (n=7) with AZA in combination (2 pts with lenalidomide and 5 pts with investigational agents)) with 18% (n=13) receiving decitabine. The median # of HMA cycles was 4 (range 1-33). Thirteen pts (18%) proceeded to allogeneic hematopoietic stem cell transplant (HSCT). Of the cohort, 18% (n=13) obtained complete remission (CR) with 39% (n=28) overall response rate (ORR). There was no difference in CR or ORR in pts treated with AZA vs DAC (P=0.24 and P=0.2, respectively). At a median follow up 20 months, the median OS of the entire cohort was 9.7 months. There was no difference in median OS between AZA vs AZA combo vs DAC (7.6 vs 15.2 vs 12.5 months; P = 0.44; Figure 1A). TP53 variant allele frequency (VAF > 20% vs ≤ 20%) was not predictive of outcomes to HMA (7.8 vs 10.4 months, P = 0.36). However, TP53 MT patients who had clonal response to HMA (i.e. VAF < 5%; n=19 (27%)) had improved OS (14.5 vs 7.5 months; HR 0.33, 95% CI 0.18 to 0.59; P = 0.001; Figure 1B). In multivariable analysis incorporating age, revised international prognostic scoring system (IPSS-R) category, HSCT status, or type of HMA, TP53 clonal clearance remained an independent covariate for improved OS (HR 0.34, 95% CI 0.16 to 0.72; P = 0.005). Pts who underwent HSCT (n=13) had a trend for improved OS (14.5 months vs 7.9 months; P = 0.09). Notably in transplanted pts who had serial TP53 NGS (n=7), pts who achieved a VAF < 5% had significant improved OS (16.3 months vs 8.9 months; P=0.03). Compared to higher risk MDS/AML TP53 WT patients treated with HMA, there was no difference in CR (18% vs 14% (P = 0.64) or ORR rates (39% vs 40%). In contrast, TP53 MT patients had significantly inferior OS with HMA therapy (9.7 vs 15.4 months; HR 2.14, 95% CI 1.32. to 3.27; P = 0.001; Figure 1C). Conclusion In this large cohort of higher risk MDS and oligoblastic AML pts who received frontline HMA therapy, TP53 MT patients have significantly inferior OS with no significant differences in response rates or outcomes by HMA. TP53 MT patients who achieve maximum clonal suppression with HMA treatment (i.e. VAF < 5%) have improved OS as well as improved outcome with HSCT. Novel therapy targeting TP53 mutation is needed to improve outcomes. Figure 1. Figure 1. Disclosures Sallman: Celgene: Research Funding, Speakers Bureau. Sweet:Agios: Consultancy; Jazz: Speakers Bureau; Astellas: Consultancy; Phizer: Consultancy; Phizer: Consultancy; Astellas: Consultancy; Jazz: Speakers Bureau; Celgene: Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Agios: Consultancy; BMS: Honoraria; Celgene: Honoraria, Speakers Bureau; BMS: Honoraria. List:Celgene: Research Funding. Komrokji:Novartis: Honoraria, Speakers Bureau; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Speakers Bureau.

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Prognosis and Outcomes in MDS-MPN Unclassifiable: Single Institution Experience of a Rare Disorder

Blood ◽

10.1182/blood.v126.23.1698.1698 ◽

2015 ◽

Vol 126 (23) ◽

pp. 1698-1698 ◽

Cited By ~ 2

Author(s):

Ateefa Chaudhury ◽

Rami S. Komrokji ◽

Najla H. Al Ali ◽

Ling Zhang ◽

Pardis Vafaii ◽

...

Keyword(s):

Overall Survival ◽

Risk Stratification ◽

Scoring System ◽

Lower Risk ◽

Research Funding ◽

Median Overall Survival ◽

Scoring Systems ◽

Rare Disorder ◽

International Prognostic Scoring System ◽

Cancer Center

Abstract Introduction: The 2008 World Health Organization (WHO) classification has recognized a unique overlap category that has features of proliferation found in myeloproliferative neoplasms (MPN) and also dysplasia found in myelodysplastic syndrome (MDS). The least well characterized of the 4 MDS/MPN overlap diseases is a rare entity known as MDS/MPN Unclassifiable (MDS/MPN-U), comprising <5% of myeloid disorders. Furthermore, given the rarity of this disorder, there is no validated risk stratification scoring system, although there are several commonly used prognostic models for MDS, including the International Prognostic Scoring System (IPSS), the Revised International Prognostic Scoring System (IPSS-R), and the M.D. Anderson Cancer Center model (MDAS). The objectives of this study were to evaluate the natural history of this very uncommon diagnosis and to determine which of the current scoring symptoms used for MDS best discriminates outcomes. Methods: The Moffitt Cancer Center database of over 3000 MDS patients was used to identify patients with MDS/MPN-U and to subsequently perform a comprehensive chart/pathology review. We then applied IPSS, IPSS-R, and the MDAS scores to each patient in order to compare differences in overall survival (OS) amongst different risk groups within each scoring system. Finally, we compared outcomes in the MDS/MPN-U group with a large number of matched MDS cases from within our database, using the MDAS. Descriptive statistical analyses were utilized. Chi square analysis and t- test were performed to compare categorical and continuous variables. Akaike information criteria (AIC) were used to assess the relative goodness of fit of the models. All data was analyzed using SPSS version 21.0 statistical software. Results: Forty three patients were identified with MDS/MPN-U and were pathologically confirmed to meet WHO criteria. Median age was 71 years (range 55 - 91) and the M:F = 26.17. Median baseline laboratory parameters: WBC 11.2 x 103/dL (range 0.9 - 84.8); Hb 9.7 g/dL (range 5.8-14.4); platelets 137 x 103/uL. Table 1 summarizes risk stratification per current validated MDS scoring systems. The majority of patients had lower risk disease by all the models. Forty of 42 (95%) patients evaluable for prognostic scoring were classified as low/Int-1 by IPSS. However, 11 out of the 40 pts (28%) classified as lower risk by IPSS were upgraded to Int-2 or high risk by MDAS. Twenty-two patients received hypomethylating agents (HMA) as first line treatment after supportive care. Per IWG 2006, 8 of 22, (36%) had complete response, partial remission, or hematologic improvement, 7 (32%) had stable disease, and 6 (27%) had progressive disease. The median OS for all MDS/MPN-U patients was 33 months (95% Confidence Interval 22 - 45). Within each MDS scoring system, statistically significant survival differences were detected between risk stages (table 1). The IPSS-R did not improve the IPSS prognostic value. Patients categorized as lower-risk (low/Int-1) by MDAS had superior survival compared to IPSS. Lastly, we compared outcomes between the 43 MDS/MPN-U patients and 1117 IPSS low/Int-1 matched controls within the MDS database. Median overall survival was inferior in MDS/MPN-U vs. MDS (33.4 mo vs. 57 mo, p = 0.005). In addition, using the MDAS, stage-by-stage, survival was significantly worse in the MDS/MPN-U group. Table 1. Risk Stratification Based on MDS Scoring Systems MDS/MPN-Un (%) Median Overall Survival (mo) P-value IPSS Low Int-1 Int-2 High 15 (35.7)25 (59.5)1 (2.4)1 (2.4) 33.433.312.86.0 < 0.001 IPSS-R Very Low Low Intermediate High Very High 6 (14.3)21 (50)10 (23.8)4 (9.5)1 (2.4) 18.2333.425.112.86.0 0.001 MDAS Low Int-1 Int-2 High 6 (14.3)20 (47.6)13 (31.0)3 (7.1) 52.433.425.16.0 < 0.001 Conclusions: MDS/MPN-U appears to have a variable disease course but with generally poor outcomes, even amongst lower-risk patients classified by MDS scoring systems, and despite a moderate rate of response to treatment. Matched comparisons indicate inferior outcomes compared with similarly staged MDS patients. The MDAS may offer increased discriminatory capacity for determining prognosis based on disease stage. Further work with a larger patient population and cross comparisons to other MDS/MPN diseases will assist further understanding of this rare disorder. Integration of somatic mutations data may compliment the clinical models. Disclosures Komrokji: Novartis: Research Funding, Speakers Bureau; Celgene: Consultancy, Research Funding; Pharmacylics: Speakers Bureau; Incyte: Consultancy. Lancet:Kalo-Bios: Consultancy; Celgene: Consultancy, Research Funding; Pfizer: Research Funding; Amgen: Consultancy; Seattle Genetics: Consultancy; Boehringer-Ingelheim: Consultancy.

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CIRCULATING microRNA EXPRESSION IN MYELODYSPLASTIC SYNDROME

Liječnički vjesnik ◽

10.26800/lv-141-7-8-30 ◽

2019 ◽

Vol 141 (7-8) ◽

pp. 233-237

Keyword(s):

Bone Marrow ◽

Myelodysplastic Syndrome ◽

Peripheral Blood ◽

Scoring System ◽

Molecular Mechanisms ◽

International Prognostic Scoring System ◽

Circulating Microrna ◽

Hematopoietic Stem ◽

The Impact

Myelodysplastic syndrome (MDS) is a clonal hematopoietic stem cell disorder characterized by ineffective hematopoiesis and cytopenia in peripheral blood, where about a third of patients may develop acute myeloid leukemia (AML). The diagnosis of MDS requires the analysis of peripheral blood and bone marrow. Depending on the percentage of blasts in the bone marrow, the number of cytopenias and cytogenetic abnormalities, determination of the prognostic indices is possible (IPSS – „International Prognostic Scoring System“, R-IPSS-„Revised International Prognostic Scoring System“, WPSS – „WHO Prognostic Scoring System“). Until today, numerous studies have been conducted on the molecular mechanisms and epigenetic pathways in myelodysplastic syndrome, and their prognostic and therapeutic importance, but there are few studies analyzing the importance of microRNAs (miRNAs) in MDS. In the last few years, there have been numerous results on the impact of aberrant miRNA expression in malignant disorders where the miRNA represent tumor suppressor genes or oncogenes. Several miRNAs have been recognized as diagnostic and prognostic parameters and possible therapeutic targets. In this paper, we present the overview of recent results on the role of miRNA in MDS.

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Lower Hematopoietic Progenitor Cell Counts and Yields at Subsequent Donations Is Influenced By a Shorter Inter-Donation Interval between the First and Subsequent Mobilizations

Blood ◽

10.1182/blood-2019-123492 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 1962-1962

Author(s):

Sandhya R. Panch ◽

Brent R. Logan ◽

Jennifer A. Sees ◽

Bipin N. Savani ◽

Nirali N. Shah ◽

...

Keyword(s):

Stem Cell ◽

Board Of Directors ◽

Peripheral Blood ◽

Research Funding ◽

Time Interval ◽

Advisory Committees ◽

Hematopoietic Stem ◽

Peripheral Blood Cd34 ◽

Cell Counts ◽

Cd34 Cells

Introduction: Approximately 7% of unrelated hematopoietic stem cell (HSC) donors are asked to donate a subsequent time to the same or different recipient. In a recent large CIBMTR study of second time donors, Stroncek et al. incidentally found that second peripheral blood stem cell (PBSC) collections had lower total CD34+ cells, CD34+ cells per liter of whole blood processed, and CD34+ cells per kg donor weight. Based on smaller studies, the time between the two independent PBSC donations (inter-donation interval) as well as donor sex, race and baseline lymphocyte counts appear to influence CD34+ cell yields at subsequent donations. Our objective was to retrospectively evaluate factors contributory to CD34+ cell yields at subsequent PBSC donation amongst NMDP donors. Methods. The study population consisted of filgrastim (G-CSF) mobilized PBSC donors through the NMDP/CIBMTR between 2006 and 2017, with a subsequent donation of the same product. evaluated the impact of inter-donation interval, donor demographics (age, BMI, race, sex, G-CSF dose, year of procedure, need for central line) and changes in complete blood counts (CBC), on the CD34+ cell yields/liter (x106/L) of blood processed at second donation and pre-apheresis (Day 5) peripheral blood CD34+ cell counts/liter (x106/L) at second donation. Linear regression was used to model log cell yields as a function of donor and collection related variables, time between donations, and changes in baseline values from first to second donation. Stepwise model building, along with interactions among significant variables were assessed. The Pearson chi-square test or the Kruskal-Wallis test compared discrete variables or continuous variables, respectively. For multivariate analysis, a significance level of 0.01 was used due to the large number of variables considered. Results: Among 513 PBSC donors who subsequently donated a second PBSC product, clinically relevant decreases in values at the second donation were observed in pre-apheresis CD34+ cells (73.9 vs. 68.6; p=0.03), CD34+cells/L blood processed (32.2 vs. 30.1; p=0.06), and total final CD34+ cell count (x106) (608 vs. 556; p=0.02). Median time interval between first and second PBSC donations was 11.7 months (range: 0.3-128.1). Using the median pre-apheresis peripheral blood CD34+ cell counts from donation 1 as the cut-off for high versus low mobilizers, we found that individuals who were likely to be high or low mobilizers at first donation were also likely to be high or low mobilizers at second donation, respectively (Table 1). This was independent of the inter-donation interval. In multivariate analyses, those with an inter-donation interval of >12 months, demonstrated higher CD34+cells/L blood processed compared to donors donating within a year (mean ratio 1.15, p<0.0001). Change in donor BMI was also a predictor for PBSC yields. If donor BMI decreased at second donation, so did the CD34+cells/L blood processed (0.74, p <0.0001). An average G-CSF dose above 960mcg was also associated with an increase in CD34+cells/L blood processed compared to donors who received less than 960mcg (1.04, p=0.005). (Table 2A). Pre-apheresis peripheral blood CD34+ cells on Day 5 of second donation were also affected by the inter-donation interval, with higher cell counts associated with a longer time interval (>12 months) between donations (1.23, p<0.0001). Further, independent of the inter-donation interval, GCSF doses greater than 960mcg per day associated with higher pre-apheresis CD34+ cells at second donation (1.26, p<0.0001); as was a higher baseline WBC count (>6.9) (1.3, p<0.0001) (Table 2B). Conclusions: In this large retrospective study of second time unrelated PBSC donors, a longer inter-donation interval was confirmed to be associated with better PBSC mobilization and collection. Given hematopoietic stem cell cycling times of 9-12 months in humans, where possible, repeat donors may be chosen based on these intervals to optimize PBSC yields. Changes in BMI are also to be considered while recruiting repeat donors. Some of these parameters may be improved marginally by increasing G-CSF dose within permissible limits. In most instances, however, sub-optimal mobilizers at first donation appear to donate suboptimal numbers of HSC at their subsequent donation. Disclosures Pulsipher: CSL Behring: Membership on an entity's Board of Directors or advisory committees; Miltenyi: Research Funding; Bellicum: Consultancy; Amgen: Other: Lecture; Jazz: Other: Education for employees; Adaptive: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Medac: Honoraria. Shaw:Therakos: Other: Speaker Engagement.

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Plerixafor (Mozobil ®)Plus G-CSF Is Effective in Mobilizing Hematopoietic Stem Cells in Patients with Concurrent Thrombocytopenia Undergoing Autologous Hematopoietic Stem Cell Transplantation.

Blood ◽

10.1182/blood.v114.22.3229.3229 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3229-3229 ◽

Cited By ~ 1

Author(s):

Ivana N Micallef ◽

Eric Jacobsen ◽

Paul Shaughnessy ◽

Sachin Marulkar ◽

Purvi Mody ◽

...

Keyword(s):

Stem Cell ◽

Platelet Count ◽

Board Of Directors ◽

Research Funding ◽

Advisory Committees ◽

Hematopoietic Stem ◽

Platelet Counts ◽

Cd34 Cells ◽

Low Platelet Count ◽

Equity Ownership

Abstract Abstract 3229 Poster Board III-166 Introduction Low platelet count prior to mobilization is a significant predictive factor for mobilization failure in patients with non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD) undergoing autologous hematopoietic stem cell (HSC) transplantation (auto-HSCT; Hosing C, et al, Am J Hematol. 2009). The purpose of this study is to assess the efficacy of HSC mobilization with plerixafor plus G-CSF in patients with concomitant thrombocytopenia undergoing auto-HSCT. Methods Patients who had failed successful HSC collection with any mobilization regimen were remobilized with plerixafor plus G-CSF as part of a compassionate use program (CUP). Mobilization failure was defined as the inability to collect 2 ×106 CD34+ cells/kg or inability to achieve a peripheral blood count of ≥10 CD34+ cells/μl without having undergone apheresis. As part of the CUP, G-CSF (10μg/kg) was administered subcutaneously (SC) every morning for 4 days. Plerixafor (0.24 mg/kg SC) was administered in the evening on Day 4, approximately 11 hours prior to the initiation of apheresis the following day. On Day 5, G-CSF was administered and apheresis was initiated. Plerixafor, G-CSF and apheresis were repeated daily until patients collected the minimum of 2 × 106 CD34+ cells/kg for auto-HSCT. Patients in the CUP with available data on pre-mobilization platelet counts were included in this analysis. While patients with a platelet count <85 × 109/L were excluded from the CUP, some patients received waivers and were included in this analysis. Efficacy of remobilization with plerixafor + G-CSF was evaluated in patients with platelet counts ≤ 100 × 109/L or ≤ 150 × 109/L. Results Of the 833 patients in the plerixafor CUP database, pre-mobilization platelet counts were available for 219 patients (NHL=115, MM=66, HD=20 and other=18.). Of these, 92 patients (NHL=49, MM=25, HD=8 and other=10) had pre-mobilization platelet counts ≤ 150 × 109/L; the median platelet count was 115 × 109/L (range, 50-150). The median age was 60 years (range 20-76) and 60.4% of the patients were male. Fifty-nine patients (64.1%) collected ≥2 × 109 CD34+ cells/kg and 13 patients (14.1%) achieved ≥5 × 106 CD34+ cells/kg. The median CD34+ cell yield was 2.56 × 106 CD34+ cells/kg. The proportion of patients proceeding to transplant was 68.5%. The median time to neutrophil and platelet engraftment was 12 days and 22 days, respectively. Similar results were obtained when efficacy of plerixafor + G-CSF was evaluated in 29 patients with platelet counts ≤ 100 × 109/L (NHL=12, MM=10, HD=3 and other=4). The median platelet count in these patients was 83 × 109/L (range, 50-100). The median age was 59 years (range 23-73) and 60.4% of the patients were male. The minimal and optimal cell dose was achieved in 19(65.5%) and 3(10.3%) patients, respectively. The median CD34+ cell yield was 2.92 × 106 CD34+ cells/kg. The proportion of patients proceeding to transplant was 62.1%. The median time to neutrophil and platelet engraftment was 12 days and 23 days, respectively. Conclusions For patients mobilized with G-CSF alone or chemotherapy ±G-CSF, a low platelet count prior to mobilization is a significant predictor of mobilization failure. These data demonstrate that in patients with thrombocytopenia who have failed prior mobilization attempts, remobilization with plerixafor plus G-CSF allows ∼65% of the patients to collect the minimal cell dose to proceed to transplantation. Thus, in patients predicted or proven to be poor mobilizers, addition of plerixafor may increase stem cell yields. Future studies should investigate the efficacy of plerixafor + G-CSF in front line mobilization in patients with low platelet counts prior to mobilization. Disclosures Micallef: Genzyme Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Jacobsen:Genzyme Corporation: Research Funding. Shaughnessy:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Marulkar:Genzyme Corporation: Employment, Equity Ownership. Mody:Genzyme Corporation: Employment, Equity Ownership. van Rhee:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

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Major Improvement of Invasive Aspergillosis Outcome Is Not Enough to Improve Overall Survival In Allogeneic Hematopoietic Stem Cell Transplant Recipients: Results From a Single-Center Retrospective Analysis

Blood ◽

10.1182/blood.v116.21.1244.1244 ◽

2010 ◽

Vol 116 (21) ◽

pp. 1244-1244

Author(s):

Géraldine Salmeron ◽

Raphaël Porcher ◽

Anne Bergeron ◽

Marie Robin ◽

Regis Peffault de Latour ◽

...

Keyword(s):

Overall Survival ◽

Board Of Directors ◽

Cumulative Incidence ◽

Research Funding ◽

Line Treatment ◽

First Line ◽

Advisory Committees ◽

Hematopoietic Stem ◽

Risk Of Death ◽

First Line Treatment

Abstract Abstract 1244 Background. Voriconazole (V) treatment has been shown to improve the 12 week (W) survival rate of hematological patients (pts) with invasive aspergillosis (IA), including recipients of allogeneic hematopoietic stem cell transplants (HSCT). We investigated whether this early survival advantage could translate into a significant increase in overall survival. Methods. We retrospectively reviewed all consecutive pts who received a transplant between Sept. 1997 and Dec. 2008 at Saint-Louis Hospital and were diagnosed as having IA. The temporal origin of the study was the date of IA diagnosis for each patient. Factors associated with survival were analyzed using Cox proportional hazard models. Separate models were estimated for survival up to 12 W and for survival between 12 W and 24 months (M) in pts surviving longer than 12 W. The deaths of pts with and without IA were analyzed with a competing risk framework. Cumulative incidence curves were compared using Gray's tests. Results. Our study examined 89 IA pts. The median follow-up was 70 M (range, 11–130 M). Two pts did not receive any antifungal treatment and were excluded from subsequent analyses. Of the 87 pts, 42 received first-line V and 45 primarily received a lipid formulation of amphotericin B (n=25), amphotericin B deoxycholate (n=10), caspofungin (n=8) or itraconazole (n=2). The primary characteristics of pts with IA and their causes of death, separated by V as first-line treatment, are shown in the table below. The median survival was 2.6 M, and the overall survival at 24 M was 19% (95% CI 12–30 M) (see figure). Overall, the survival rates of the two groups were significantly different (P= 0.010). However, the differences in survival were quite dramatic prior to 10 M, whereas both survival curves became very close after one year. At 18 M, the numbers of surviving pts were almost identical in the two groups [19% (95% CI: 11–34%) in pts who did not receive V as first-line treatment vs. 21% (95% CI 11–38%) in pts who did]. Pts who did not receive V as a first-line treatment displayed a higher probability of dying from IA than those who did (P=0.004), whereas opposite results were found for mortality in pts without IA (P=0.006). The 24-M cumulative incidence of death from IA was 47% (95% CI 31–61%) in the no V group and 19% (95% CI 9–33%) in the group treated with V. The 24-M cumulative incidence of death in pts without IA was 4% (95% CI 7–14%) in the no V group and 27% (95% CI 14–42%) in pts treated with V. The probability of death from another cause, with IA, was similar in both groups (29% vs. 36% at 24 M; P=0.46). After adjusting for donor type, conditioning regimen, progressive GVHD at diagnosis of IA and cumulated steroid dose (mg/kg) in the W preceding IA diagnosis, administration of V as first-line treatment was found to decrease the risk of death during the first 12 W by approximately 70% [HR=0.31 (95% CI 0.16–0.60); P=0.0005]. Conversely, analysis of mortality between 12 W and 24 M failed to identify any significant predictor of risk of death; however, only 24 pts died during this period. Conclusions. The finding that first-line treatment with V, which is associated with a tremendous improvement in IA outcome, does not translate into an increase in overall survival (even in the context of early diagnosis) is striking. Diagnosis of IA following HSCT, whatever the outcome, appears to be a strong marker for poor long-term prognosis. Disclosures: Bergeron: Pfizer: Speakers Bureau, none; Merck: Speakers Bureau, none; Schering: Speakers Bureau, none. Sulahian:Pfizer: Research Funding, non; Merck: Research Funding, none. Ribaud:Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau, none; Schering: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau, none; Gilead: Speakers Bureau, none.

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Azacitidine (Vidaza®, Aza) and Donor Lymphocyte Infusions (DLI) In Patients with Acute Myeloid Leukemia (AML) or Myelodysplastic Syndromes (MDS) Relapsing After Allogeneic Hematopoietic Stem Cell Transplantation (HSCT): Interim-Analysis From the AZARELA-Trial (NCT-00795548).

Blood ◽

10.1182/blood.v116.21.1294.1294 ◽

2010 ◽

Vol 116 (21) ◽

pp. 1294-1294

Author(s):

Thomas Schroeder ◽

Akos Gabor Czibere ◽

Nicolaus Kröger ◽

Uwe Platzbecker ◽

Gesine Bug ◽

...

Keyword(s):

Overall Survival ◽

Missing Data ◽

Salvage Therapy ◽

Interim Analysis ◽

Research Funding ◽

Acute Gvhd ◽

Chronic Gvhd ◽

Significant Activity ◽

Hematopoietic Stem ◽

Allogeneic Hsct

Abstract Abstract 1294 Background: Patients with AML or MDS who relapse after allogeneic HSCT have a poor prognosis and therapeutic options are limited. The DNA hypomethylating agent Aza has significant activity in patients (pts) with AML and MDS and retrospective analyses have recently shown encouraging results with the use of Aza +/− DLI in patients with AML and MDS, who relapsed after allogeneic HSCT (Czibere et al., 2010; Luebbert et al., 2010). In line with these clinical observations preclinical data suggest that Aza enhances a Graft-versus-Leukemia (GvL) effect while mitigating Graft-versus-Host Disease (GvHD). Design/Methods: To evaluate the activity and safety of Aza in combination with DLI as first salvage therapy in pts with AML or MDS relapsing after HSCT, we conducted a prospective, multicenter, single-arm phase-II trial. Pts were allowed to receive up to 8 cycles Aza (100 mg/m2/d d1-5, every 28 days) and 3 DLI with increasing dosages (1-5×106 – 1–5×108 cells/kg) after every 2nd Aza treatment cycle. Additional DLI were permitted. Results: Between January 2009 and May 2010, 30 pts from 6 German transplant centres were included into this trial. So far, 25 pts (15 female/10 male) were evaluable and are presented in this analysis: Of these, 23 (92%) suffered from AML (15 de novo/8 secondary following MDS), 1(4%) from a MDS (RAEB-1) and 1 (4%) from a myelodysplastic/myeloproliferative syndrome (MDS/MPS, CMML-1). Median age was 54 years (range 29–71). Conditioning was myeloablative in 24 pts (96%) and non-myeloablative in 1 patient (4%). Eight pts (35%) received a graft from a matched sibling donor, while 15 (65%) were transplanted with a matched unrelated donor (2 pts missing data). Peripheral blood stem cells (PBSC) were used in 24 pts (96%; 1 pt missing data). At the time of transplant 6 pts (24%) had primary induction failure, another 6 (24%) suffered from first or secondary relapse, 10 pts (40%) were in first or second complete remission (CR), while 3 pts (12%) were untreated. With regard to their molecular and genetic characteristics at diagnosis, 21 pts belonged to an adverse (9 pts) or intermediate (12 pts) group, whereas 2 pts were diagnosed with a favourable genetic phenotype (2 pts not performed). Prior to relapse 9 (36%) and 3 (12%) pts had episodes of acute GvHD and/or chronic GvHD, respectively. Relapse occurred in all pts after a median of 160 days (range 19–1199) following HSCT (median BM blasts: 34%, range 5–100%, median chimerism: 63% range-1-100%). At the time of relapse, karyotype was evaluable in 13 of 25 pts (52%). Of these 13 pts, 4 pts had a normal karyotype, while 9 had chromosomal aberrations including 6 pts with a complex karyotype. Patients received a median of 3 courses Aza (range 1–8) and 18 of 25 pts (72%) received DLI (median: 1, range: 1–4, median CD3 dose 5×106/kg/DLI, range: 1–207×106). Following treatment, overall response rate was 64% with 5 pts (20%) achieving a CR or CRi, 3 (12%) a partial remission (PR) and 8 (32%) a stable disease (SD). Median response duration was 266 days. Acute GvHD occurred in 6 pts (24%) (2 skin/6 liver/ 2 gut) after a median of 65 days (range 19–179) following the first DLI, while chronic GvHD was observed in 3 pts (12 %, all limited). Hematotoxicity (grade III-IV) was observed in 64% of all evaluated patients. Common adverse events were gastrointestinal side effects as well as infections. After a median follow-up of 100 days (range 25–485) 15 of 25 pts (60%) are currently alive. Median overall survival of all pts is 184 days (range 87–281). All pts, who achieved a CR/CRi, remained in ongoing remission for a median time of 229 days. Achieving a CR (CR: not reached vs. no CR: 117 days, p .008) or any type of response (CR/CRi, PR or SD) to the combination of Aza and DLI (any response: not reached vs. no response: 79 days, p .0001) were associated with a significantly longer overall survival. Conclusion: The combination of Aza and DLI as salvage treatment for patients with AML or MDS who relapse after allogeneic HSCT seems to be safe and shows significant anti-leukemic activity. Response, including CR rates, so far match those from retrospective analyses. Data presented in this interim-analysis suggest that salvage therapy with Aza and DLI is of substantial therapeutic benefit in these challenging patients. Disclosures: Platzbecker: Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Bug:Celgene: Honoraria. Luft:Celgene: Research Funding. Fenk:Celgene: Research Funding. Kobbe:Celgene: Research Funding.

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Hematopoietic Stem Cell Transplantation for Myelodysplastic Syndrome and Chronic Myelomonocytic Leukemia In Patients up to Age 75: Comparison of Survival In Patients with An Available Donor Compared to Patients without a Donor

Blood ◽

10.1182/blood.v116.21.2381.2381 ◽

2010 ◽

Vol 116 (21) ◽

pp. 2381-2381

Author(s):

Teresa Field ◽

Janelle Perkins ◽

Taiga Nishihori ◽

Joseph Pidala ◽

Hugo F. Fernandez ◽

...

Keyword(s):

Overall Survival ◽

Survival Analysis ◽

Myelodysplastic Syndrome ◽

Cell Transplantation ◽

Research Funding ◽

Chronic Myelomonocytic Leukemia ◽

No Donor ◽

Hematopoietic Stem ◽

Myelomonocytic Leukemia

Abstract Abstract 2381 Allogeneic hematopoietic cell transplantation (HCT) remains the only curative treatment strategy for patients with Myelodysplastic Syndrome (MDS) or Chronic Myelomonocytic Leukemia (CMML). Recent reduction of the transplant related toxicity has permitted the expansion of empiric age limitations for HCT up to 75 years. There has been limited comparative data on HCT focusing on donor availability in patients with MDS/CMML. Between January 2004 and September 2009, a total of 255 new patients (NP) with a diagnosis of MDS or CMML were evaluated for HCT at Moffitt Cancer Center. This report describes the outcomes of these patients with emphasis on donor availability. Donor Search Results: Of the 255 NP, 58 did not undergo a donor search. Reasons for not proceeding were as follows: Medicare declined coverage due to age >65 (18), waiting as have low risk disease (15), patient declined (6), patient seen as second opinion only (7) and patient was not eligible for HCT (12). These patients were not included in the survival analysis. Of the 197 patients who had a donor search initiated, a sibling (SIB) matched unrelated (MUD) or single HLA antigen/allele mismatch (mMUD) unrelated adult donor was found in 173 patients. A suitable adult donor was not identified in the remaining 24 patients. To mitigate bias due to factors giving a survival advantage to patients who were stable enough to survive the donor and proceed to HCT, the survival analysis included only those patients alive 90 days after the donor search was initiated. We have been able to identify donors within this time frame for 99% of the patients who ever found one, although time to transplant is longer. At the 90 days landmark, there were 164 patient in the Donor cohort, and 19 patients in the No Donor cohort. Donor Cohort: The median age was 56.6 yrs (18.5 – 73.5). Ninety-seven patients (59%) were older than 55 yrs and 26 (16%) were above 65 yrs. At the time of the transplant consult, IPSS risk was Low (10), Int-1 (44), Int-2 (48), High (25), AML (21), CMML (13), or not evaluable (NE) (3). Donors included SIB (60), MUD (75) and mMUD (29). Median follow-up of surviving patients is 27.7months (7.2 – 70.7). No Donor Cohort: Median age was 57.4 yrs (32.6 – 68.1) with 12 patients (63%) older than 55 yrs and 3 (16%) patients older than 65 years of age. IPSS at initiation of the donor search was Int-1 (5), Int-2 (6), High (5), AML (1) and CMML (2). Median follow-up is 9.2 months (1.4 – 61.5). Of the 19 patients with no donor, 3 patients received an umbilical cord blood HCT elsewhere and were analyzed by intent to treat. Outcomes: Patients with a donor had significantly improved overall survival from time of donor search vs. patients with no donor (P=0.007) with 2 year OS of 48% vs. 23%, respectively. Median survival for the donor group was 22.2 months [95% CI 14.7 – 35.7] vs. 10.1 months for those without a donor [95% CI 2.3 – 14.7]. Transplant: Of the 164 patients with a donor, 121 (74%) patients received the planned allogenic transplants. The 2-year overall survival (OS) after transplantation is similar for SIB (51%), MUD (39%) or mMUD (68%) transplant recipients (P=0.4), and also similar by age below or above 55 years (P=0.7). These data demonstrate that most patients with MDS or CMML can have a suitable donor identified and proceed to HCT. Overall survival is significantly improved for those patients who have a suitable sibling or unrelated donor. Disclosures: Lancet: Eisai: Consultancy; Celgene: Honoraria. Alsina: Millenium: Consultancy, Research Funding; Celgene: Research Funding; Novartis: Consultancy. List: Celgene: Research Funding.

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Anti-CD123 Chimeric Antigen Receptor T Cells (CART-123) Provide A Novel Myeloablative Conditioning Regimen That Eradicates Human Acute Myeloid Leukemia In Preclinical Models

Blood ◽

10.1182/blood.v122.21.143.143 ◽

2013 ◽

Vol 122 (21) ◽

pp. 143-143 ◽

Cited By ~ 4

Author(s):

Saar Gill ◽

Sarah K Tasian ◽

Marco Ruella ◽

Olga Shestova ◽

Yong Li ◽

...

Keyword(s):

Bone Marrow ◽

T Cells ◽

Research Funding ◽

Conditioning Regimen ◽

Hematopoietic Stem ◽

Gm Csf ◽

Nsg Mice ◽

Cd34 Cells ◽

Society Research

Abstract Engineering of T cells with chimeric antigen receptors (CARs) can impart novel T cell specificity for an antigen of choice, and anti-CD19 CAR T cells have been shown to effectively eradicate CD19+ malignancies. Most patients with acute myeloid leukemia (AML) are incurable with standard therapies and may benefit from a CAR-based approach, but the optimal antigen to target remains unknown. CD123, the IL3Rα chain, is expressed on the majority of primary AML specimens, but is also expressed on normal bone marrow (BM) myeloid progenitors at lower levels. We describe here in vitro and in vivostudies to evaluate the feasibility and safety of CAR-based targeting of CD123 using engineered T cells (CART123 cells) as a therapeutic approach for AML. Our CAR consisted of a ScFv derived from hybridoma clone 32716 and signaling domains from 4-1-BB (CD137) and TCR-ζ. Among 47 primary AML specimens we found high expression of CD123 (median 85%, range 6-100%). Quantitative PCR analysis of FACS-sorted CD123dim populations showed measurable IL3RA transcripts in this population, demonstrating that blasts that are apparently CD123dim/neg by flow cytometry may in fact express CD123. Furthermore, FACS-sorted CD123dimblasts cultured in methylcellulose up-regulated CD123, suggesting that anti-CD123 immunotherapy may be a relevant strategy for all AML regardless of baseline myeloblast CD123 expression. CART123 cells incubated in vitro with primary AML cells showed specific proliferation, killing, and robust production of inflammatory cytokines (IFN-α, IFN-γ, RANTES, GM-CSF, MIP-1β, and IL-2 (all p<0.05). In NOD-SCID-IL2Rγc-/- (NSG) mice engrafted with the human AML cell line MOLM14, CART123 treatment eradicated leukemia and resulted in prolonged survival in comparison to negative controls of saline or CART19-treated mice (see figure). Upon MOLM14 re-challenge of CART123-treated animals, we further demonstrated robust expansion of previously infused CART123 cells, consistent with establishment of a memory response in animals. A crucial deficiency of tumor cell line models is their inability to represent the true clonal heterogeneity of primary disease. We therefore engrafted NSG mice that are transgenic for human stem cell factor, IL3, and GM-CSF (NSGS mice) with primary AML blasts and treated them with CART123 or control T cells. Circulating myeloblasts were significantly reduced in CART123 animals, resulting in improved survival (p = 0.02, n=34 CART123 and n=18 control animals). This observation was made regardless of the initial level of CD123 expression in the primary AML sample, again confirming that apparently CD123dimAML may be successfully targeted with CART123 cells. Given the potential for hematologic toxicity of CART123 immunotherapy, we treated mice that had been reconstituted with human CD34+ cells with CART123 cells over a 28 day period. We observed near-complete eradication of human bone marrow cells. This finding confirmed our finding of a significant reduction in methylcellulose colonies derived from normal cord blood CD34+ cells after only a 4 hour in vitro incubation with CART123 cells (p = 0.01), and was explained by: (i) low level but definite expression of CD123 in hematopoietic stem and progenitor cells, and (ii) up-regulation of CD123 upon myeloid differentiation. In summary, we show for the first time that human CD123-redirected T cells eradicate both primary human AML and normal bone marrow in xenograft models. As human AML is likely preceded by clonal evolution in normal or “pre-leukemic” hematopoietic stem cells (Hong et al. Science 2008, Welch et al. Cell 2012), we postulate that the likelihood of successful eradication of AML will be enhanced by myeloablation. Hence, our observations support CART-123 as a viable therapeutic strategy for AML and as a novel cellular conditioning regimen prior to hematopoietic cell transplantation. Figure 1. Figure 1. Disclosures: Gill: Novartis: Research Funding; American Society of Hematology: Research Funding. Carroll:Leukemia and Lymphoma Society: Research Funding. Grupp:Novartis: Research Funding. June:Novartis: Research Funding; Leukemia and Lymphoma Society: Research Funding. Kalos:Novartis: Research Funding; Leukemia and Lymphoma Society: Research Funding.

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