Proof-Of-Concept Study For Precision Medicine With Chromosome Genomic Array Testing (CGAT) For Drug Sensitivity Screening In Acute Myeloid Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2578-2578
Author(s):  
Min Fang ◽  
Scott McElhone ◽  
Xin Zhao ◽  
Barry E. Storer ◽  
Su-In Lee ◽  
...  
Keyword(s):  
Myeloid Leukemia ◽  
Drug Sensitivity ◽  
Intermediate Risk ◽  
Proof Of Concept ◽  
Prognostic Effect ◽  
Genomic Array ◽  
Normal Cytogenetics ◽  
Very High ◽  
Acute Myeloid

Abstract Tremendous heterogeneity in acute myeloid leukemia (AML) poses a significant challenge to clinical management and effective therapy. Cytogenetics is one of the key prognostic factors for AML. New technologies, such as chromosome genomic array testing (CGAT) combining both SNP-based and non-SNP based array CGH, have allowed informative genomic profiling of chromosome abnormalities with very high resolution. Yet it remains unclear how these unique CGAT-identified clonal aberrations impact the outcome of AML patients and how they predict a patient’s response to a specific medication. In this proof-of-concept study, we aim to explore the correlation of genomic abnormalities identified by CGAT with in vitrodrug sensitivity data from 30 AML patients and their clinical responses. We performed CGAT on the pre-treatment bone marrow of these AML patients using CytoScanHD, which includes 2.5 million markers, 750K of which are SNP markers. Copy number aberrations (CNA) and copy-neutral loss of heterozygosity (cnLOH) were analyzed by ChAS and Nexus software. CGAT abnormalities were enumerated based on chromosome arms affected; i.e., multiple segmental CNAs and cnLOH on the same chromosome arm were counted as one aberration. Patients’ response to chemotherapy and clinical relapse were tracked. Drug sensitivity for individual patient leukemia blast samples was measured by a high-throughput in vitroassay consisting of a panel of 160 drugs, of which 45 are FDA approved and 115 investigational. Cell survival was measured by Cell Titer Glo, and data curves for 8 concentrations of each drug were generated to derive EC50 and IC50 values. Statistical correlation was analyzed by Fisher’s exact test, Cox regression, and regression analysis. CGAT detected all the chromosome abnormalities identified by cytogenetics except truly balanced translocations. CGAT also identified clonal aberrations in 7 of the 13 patients with normal cytogenetics. Of the 6 uniquely CGAT abnormal patients, 3 demonstrated cnLOH only and 2 CNA only. Overall, CGAT showed 11 complex karyotypes (CK, defined as >=3 aberrations; high-risk) and 19 normal or simple abnormal cases (low/intermediate-risk), as compared to the cytogenetics classification of 9 poor-risk, 15 intermediate-risk, and 6 low-risk karyotypes. cnLOH was detected in 9 patients (30%). Complete remission (CR) rate after the first induction course in the CGAT CK group was 18% versus 68% in the non-CK group (P=0.02). There was a very high concordance (90%) between CGAT risk based on CK and conventional cytogenetics. And when cytogenetics and CGAT disagree, as for the 2 patients who had normal cytogenetics but CGAT CK, CGAT risk stratification appeared better as neither patient achieved CR. CR duration longer than 1 year occurred more (P=0.04) in the CGAT normal patients (50%) than in the CGAT abnormal patients (8.3%). Among those who achieved CR, the hazard of relapse (HR) for CGAT CK patients was 9.9 (CI: 1.6-61; P=0.02); HR for cnLOH patients was 7.1 (CI: 1.2-43; P=0.03). Considering the total aberrations (median 1.5, range 0-16), the HR for relapse among CR patients was 1.3 (CI: 1.1-1.5; P=0.01) per aberration. Six of the 48 drugs that exhibited cytotoxicity in the in vitro assay, including clofarabine (r=0.45, P=0.01) and PKI-587 (dual PI3K/mTOR inhibitor) (r=0.48, P=0.008), showed significant correlation between CGAT aberrations and EC50; i.e, the more CGAT aberrations, the higher concentration is required for a given drug to kill these CGAT-abnormal leukemic cells in vitro. In conclusion, CGAT increased the diagnostic yield by 54% among AML patients with normal cytogenetics and altered the overall risk classification by 6.7%. Complex karyotype identified by CGAT carried the same poor prognostic effect as CK by cytogenetics. Although abnormal CGAT results did not appear to predict response, increasing CGAT abnormalities are associated with early relapse, as is the presence of cnLOH. Genomic complexity detected by CGAT appeared to associate with dosage-dependent resistance to selected drugs by in vitro drug sensitivity analyses. Characterization of prognostic effect and drug response associated with each type of CGAT abnormalities will require a larger data set. Nevertheless, this study demonstrated the clinical utility of CGAT for precision medicine in AML. Disclosures: Becker: Affymetrix: Research Funding.

Patients with FLT3 Negative Acute Myeloid Leukemia and Normal Cytogenetic who Have the Combination Mutations (NPM1-/CEBPA-) Have Better Survival Than Patients Who Have the Combination Mutations (NPM1+/CEBPA+)

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4874-4874
Author(s):  
Shamail Butt ◽  
Pascal Akl ◽  
Himanshu Bhardwaj ◽  
Samer A Srour ◽  
Terry Dunn ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Overall Survival ◽  
Acute Myeloid Leukemia ◽  
Mutation Analysis ◽  
Myeloid Leukemia ◽  
Risk Group ◽  
Intermediate Risk ◽  
Cebpa Mutations ◽  
Normal Cytogenetics ◽  
Acute Myeloid

Abstract Abstract 4874 Introduction: Acute Myeloid Leukemia (AML) is the most common type of acute leukemia in adults. About 50% of patients with AML have normal karyotype, and are categorized as intermediate risk group. However, the clinical behavior and response to treatment in this group is heterogeneous. As a result, there is strong interest in characterizing molecular genetic features in the intermediate-risk AML patients that might rectify their stratification risk. In this group, FLT3-ITD (Internal Tandem Duplication) and FLT3-TKD (Tyrosine Kinase Domain) mutations are known to confer unfavorable risk whereas NPM1 and CEBPA mutations are known to be favorable risk markers. The purpose of this study is to analyze the combination of NPM1 and CEBPA mutations in presence or absence of FLT3 mutations on prognosis of AML patients referred to the State's largest tertiary care center over a period of 10 years for the treatment of leukemia. Patients and Method: We performed a retrospective chart review of all patients with AML evaluated at University of Oklahoma Health Sciences Center between January 2000 and December 2010. Patient's age, gender, race, laboratory and clinical data as well as bone marrow biopsy and aspirate findings were reported. PCR and Fragment Analysis were conducted on all available DNA preserved bone marrow materials to test the FLT3, NPM1 and CEBPA mutations. For statistical analysis, Kaplan-Meyer curve was used. Results: A total of 239 patients were evaluated. Male to female ratio was 2/1. Median age at diagnosis was 46y. 21 out of the 239 patients were less than 18 year old. DNA samples were present on 132 patients and mutation analysis for FLT3, CEBPA and NPM1 was performed. Correlation between mutations and AML prognosis was determined. 67/132 (50.8 %) patients were categorized into intermediate risk group (majority of patients had normal cytogenetics). 14/67 (20.9%) pts were FLT3+ (FLT3-ITD or FLT3-TKD mutation). 17/67 (23.9%) were NPM1+. 7/67 (10.4%) were CEBPA +. Kaplan-Meier curve was used to identify cumulative proportion surviving over time. FLT3 presence or absence itself was not identified to be statistically significant (p 0.416) in terms of overall survival. Interestingly, presence or absence of combined NPM1/CEBPA mutation in FLT3 negative patients, among intermediate risk group, was found to be statistically significant (p<0.05) in determining overall survival. In this subgroup, presence of NPM1/CEBPA combination (NPM1+/CEBPA+) was associated with poor prognosis (figure 2, lower curve), while absence of NPM1/CEBPA combination (NPM1-/CEBPA-) carries a better prognosis (figure 2, upper curve). Conclusion: Results of our study highlight the importance of performing combinations of mutation analysis in evaluation of overall prognosis in AML patients. FLT3-/NPM1+ profile in patients with normal cytogenetics is thought to confer a favorable prognosis. We demonstrated in this study that using combination mutation analysis in patients with FLT3- can change the risk stratification in patients with intermediate risk group and might affect therapeutic interventions in this patient population. Larger prospective studies are needed in the future for further validation of our findings. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Dasatinib Inhibits FLT3/ITD and PTPN11mutated Acute Myeloid Leukemia Cells Overexpressing SRC Tyrosine Kinases

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1451-1451
Author(s):  
Sigal Tavor ◽  
Tali Shalit ◽  
Noa Chapal Ilani ◽  
Yoni Moskovitz ◽  
Nir Livnat ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Myeloid Leukemia ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Drug Sensitivity ◽  
Kinase Inhibitors ◽  
Advisory Committees ◽  
Acute Myeloid

Background: Recent advances in acute myeloid leukemia(AML) targeted therapy improve overall survival. While these targeted therapies can achieve prolonged remissions, most patients will eventually relapseunder therapy. Our recent studies suggest that relapse most often originates from several sub-clones of leukemic stem cells (LSCs), present before therapy initiation, and selected due to several resistance mechanisms. Eradication of these LSCs during treatment induction /remission could thus potentially prevent relapse. The overall goal of the current study was to identify drugs which can be safely administrated to patients at diagnosis and that will target LSCs. Since simultaneously testing multiple drugs in vivo is not feasible, we used an in vitrohigh throughput drug sensitivity assay to identify new targets in primary AML samples. Methods: Drug sensitivity and resistance testing (DSRT) was assessed in vitro (N=46 compounds) on primary AML samples from patients in complete remission (N=29). We performed whole exome sequencing and RNAseq on samples to identify correlations between molecular attributes and in vitro DSRT. Results:Unsupervised hierarchical clustering analysis of in vitro DSRT, measured by IC50, identified a subgroup of primary AML samples sensitive to various tyrosine kinase inhibitors (TKIs). In this subgroup, 52% (9/17) of AML samples displayed sensitivity to dasatinib (defined as a 10-fold decrease in IC50 compared to resistant samples). Dasatinib has broad TKI activity, and is safely administered in the treatment of leukemia. We therefore focused our analysis on predicting AML response to dasatinib, validating our results on the Beat AML cohort. Enrichment analysis of mutational variants in dasatinib-sensitive and resistant primary AML samples identified enrichment of FLT3/ITD (p=0.05) and PTPN11(p=0.05) mutations among dasatinib responders. Samples resistant to dasatinib were enriched with TP53 mutations (p=0.01). No global gene expression changes were observed between dasatinib-sensitive and resistant samples in our cohort, nor in the Beat AML cohort. Following this, we tested the differential expression of specific dasatinib-targeted genes between dasatinib-responding and resistant samples. No significant differences were identified. However, unsupervised hierarchical clustering of dasatinib targeted genes expression in our study and in the Beat AML cohort identified a subgroup of AML samples (enriched in dasatinib responders) that demonstrated overexpression of three SRC family tyrosine kinases:FGR, HCK and LYN as well as PTK6, CSK, GAK and EPHB2. Analysis of the PTPN11 mutant samples revealed that the IC50 for dasatinib in 23 carriers of the mutant PTPN11 was significantly lower compared to the IC50 of PTPN11 wild type samples (p=0.005). LYN was also upregulated (p&lt;0.001) in the mutant samples. We therefore hypothesized that gene expression of dasatinib-targeted genes could be used as a predictive biomarker of dasatinib response among FLT3/ITD carriers. We found that among FLT3/ITD AML carriers in the Beat AML cohort LYN, HCK, CSK and EPHB2 were significantly over-expressed in the dasatinib responding samples (N=27) as compared to the dasatinib resistant samples (N=35). To predict response to dasatinib among FLT3/ITD carriers we used a decision tree classifier based on the expression levels of these four genes. Our prediction model yielded a sensitivity of 74% and specificity of 83% for differentiating dasatinib responders from non-responders with an AUC of 0.84. Based on our findings, we selected FLT3/ITD AML samples and injected them to NSG-SGM3 mice. We found that in a subset of these samples, dasatinib significantly inhibited LSCs engraftment. This subset of FLT3/ITD AML samples expressed higher levels of LYN, HCK,FGR and SRC as compared to the FLT3/ITD samples that were not sensitive to dasatinib therapy in vivo. In summary, we identified a subgroup of AML patients sensitive to dasatinib, based on mutational and expression profiles. Dasatinib has anti-leukemic effects on both blasts and LSCs. Further clinical studies are needed to demonstrate whether selection of tyrosine kinase inhibitors, based on specific biomarkers, could indeed prevent relapse. Disclosures Tavor: Novartis: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; BMS companies: Membership on an entity's Board of Directors or advisory committees.

MN1 overexpression induces acute myeloid leukemia in mice and predicts ATRA resistance in patients with AML

Blood ◽  
2007 ◽  
Vol 110 (5) ◽  
pp. 1639-1647 ◽  
Author(s):  
Michael Heuser ◽  
Bob Argiropoulos ◽  
Florian Kuchenbauer ◽  
Eric Yung ◽  
Jessica Piper ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Transcriptional Repression ◽  
Myeloid Leukemia ◽  
Insertional Mutagenesis ◽  
Treatment Protocol ◽  
Predictive Marker ◽  
All Trans Retinoic Acid ◽  
Normal Cytogenetics ◽  
Acute Myeloid

AbstractOverexpression of wild-type MN1 is a negative prognostic factor in patients with acute myeloid leukemia (AML) with normal cytogenetics. We evaluated whether MN1 plays a functional role in leukemogenesis. We demonstrate using retroviral gene transfer and bone marrow (BM) transplantation that MN1 overexpression rapidly induces lethal AML in mice. Insertional mutagenesis and chromosomal instability were ruled out as secondary aberrations. MN1 increased resistance to all-trans retinoic acid (ATRA)–induced cell-cycle arrest and differentiation by more than 3000-fold in vitro. The differentiation block could be released by fusion of a transcriptional activator (VP16) to MN1 without affecting the ability to immortalize BM cells, suggesting that MN1 blocks differentiation by transcriptional repression. We then evaluated whether MN1 expression levels in patients with AML (excluding M3-AML) correlated with resistance to ATRA treatment in elderly patients uniformly treated within treatment protocol AMLHD98-B. Strikingly, patients with low MN1 expression who received ATRA had a significantly prolonged event-free (P = .008) and overall (P = .04) survival compared with patients with either low MN1 expression and no ATRA, or high MN1 expression with or without ATRA. MN1 is a unique oncogene in hematopoiesis that both promotes proliferation/self-renewal and blocks differentiation, and may become useful as a predictive marker in AML treatment.

Toward Individualized Therapy: Correlation of Mutation Analysis with in Vitro high Throughput Drug Sensitivity Testing in New Diagnosis and Relapsed Acute Myeloid Leukemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3851-3851
Author(s):  
Pamela S. Becker ◽  
Michael W. Schmitt ◽  
Zhiyi Xie ◽  
Andrew R Carson ◽  
Bradley Patay ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
High Throughput ◽  
Myeloid Leukemia ◽  
Drug Sensitivity ◽  
Missense Mutations ◽  
Sensitivity Testing ◽  
New Diagnosis ◽  
Duplex Sequencing ◽  
Acute Myeloid

Abstract Introduction: Whole genome sequencing has demonstrated tremendous heterogeneity in the mutations and chromosomal translocations associated with acute myeloid leukemia (AML), and there are several correlates with prognosis, yet we remain quite limited in our ability to predict specific chemotherapy drug sensitivity based on genomics with the exception of a few selected mutations or translocations, such as FLT3 -ITD or PML-RARA. One third of new diagnosis patients and over half of relapsed patients will not respond to initial chemotherapy regimens that incur appreciable toxicity and result in prolonged hospitalization. We therefore seek to define molecular information that might better predict response to conventional or novel therapies. Methods: MyAML™ uses next generation sequencing (NGS) to analyze the 3' and 5' UTR and exonic regions of 194 genes and potential genomic breakpoints within known somatic gene fusion breakpoints known to be associated with AML. Fragmented genomic DNA (~3.4Mb) is captured with a customized probe design, and sequenced with 300bp paired end reads on an Illumina MiSeq instrument to an average depth of coverage >1000x. Using a custom bioinformatics pipeline, MyInformatics™, single nucleotide variants (SNVs), insertion/deletions (indels), inversions and translocations are identified, annotated, characterized, and allelic frequencies calculated. Commonly associated variants in dbSNP and 1000 genomes may be eliminated, as well as variants with allele frequencies less than 5%. High throughput drug sensitivity testing was performed against a panel of 160 drugs, of which 56 are FDA approved and 104 are investigational. De-identified samples from 12 patients with de novo AML and 12 patients with relapsed AML were analyzed. For 2 patient samples, Duplex Sequencing was also performed to detect sub-clonal mutations below the detection limit of conventional NGS. Pearson and Spearman correlations were performed between all possible pairs of genes containing missense or indel mutations and the in vitro cytotoxicity response across the same set of 24 patients. Results: From the 24 patient samples analyzed to date, an average of 129 missense mutations were identified in each sample with an allelic frequency >5%. Of these, an average of over 21 missense variants were observed in COSMIC and less than 3 were novel (not in dbSNP). These samples also contained an average of over 12 coding indels (~5 frameshift and 7 inframe indels per sample). In addition, MyAML™ identified 3 samples with inv(16) and 6 samples with translocations, including the cryptic NUP98-NSD1 t(5;11) that was not detected by karyotyping. For 2 of the samples, Duplex Sequencing was performed at a depth of at least 6000X, and an accuracy of 10-7, and showed concordance of some of the mutations, with each method identifying additional mutations not observed by the other, an expected finding, as each method targeted distinct regions, and Duplex Sequencing had a greater depth of coverage. Fourteen genes were observed to exhibit at least one indel with a frameshift at frequency greater than 5% in more than one patient. In order to identify significantly associated drugs and genes containing indel mutations, we computed Pearson and Spearman correlations between drugs and these 14 genes across 24 patients. The correlation analyses revealed significant associations (p= 0.006 to 0.04) between indel mutations in three genes and chemosensitivity to drugs commonly used in AML such as cladribine, clofarabine, cytarabine, daunorubicin, etoposide, fludarabine and mitoxantrone. Similarly, significant associations (p<0.05) were identified between missense mutations in 5 genes and chemosensitivity to these drugs. Conclusion: Personalized data derived from a targeted genomic assay and in vitro chemotherapy sensitivity testing of individual patient AML samples will likely lead to innovation in treatment, identification of novel targeted agents, and improved outcomes in AML. Disclosures Xie: Invivoscribe: Employment. Carson:Genection: Employment. Patay:Genection: Employment.

High meningioma 1 (MN1) expression as a predictor for poor outcome in acute myeloid leukemia with normal cytogenetics

Blood ◽  
2006 ◽  
Vol 108 (12) ◽  
pp. 3898-3905 ◽  
Author(s):  
Michael Heuser ◽  
Gernot Beutel ◽  
Juergen Krauter ◽  
Konstanze Döhner ◽  
Nils von Neuhoff ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Prognostic Marker ◽  
Myeloid Leukemia ◽  
Performance Status ◽  
Eastern Cooperative Oncology Group ◽  
Induction Treatment ◽  
Ecog Performance Status ◽  
Normal Cytogenetics ◽  
Acute Myeloid

AbstractThe translocation t(12;22) involves MN1 and TEL and is rarely found in acute myeloid leukemia (AML). Recently, it has been shown in a mouse model that the fusion protein MN1-TEL can promote growth of primitive hematopoietic progenitor cells (HPCs) and, in cooperation with HOXA9, induce AML. We quantified MN1 expression by real-time reverse transcriptase–polymerase chain reaction (RT-PCR) in 142 adult patients with AML with normal cytogenetics treated uniformly in trial AML-SHG 01/99. AML samples were dichotomized at the median MN1 expression. High MN1 expression was significantly correlated with unmutated NPM1 (P < .001), poor response to the first course of induction treatment (P = .02), a higher relapse rate (P = .03), and shorter relapse-free (P = .002) and overall survivals (P = .03). In multivariate analysis, MN1 expression was an independent prognostic marker (P = .02) in addition to age and Eastern Cooperative Oncology Group (ECOG) performance status. Excluding patients with NPM1mutated/FLT3ITDnegative, high MN1 expression was associated with shorter relapse-free survival (P = .057). MN1 was highly expressed in some patients with acute lymphoblastic but not chronic lymphocytic or myeloid leukemia. MN1 was highly expressed in HPCs compared with differentiated cells and was down-regulated during in vitro differentiation of CD34+ cells, suggesting a functional role in HPCs. In conclusion, our data suggest MN1 overexpression as a new prognostic marker in AML with normal cytogenetics.

scholarly journals In Vitro Approach for the Identification of Exceptional Responders in Acute Myeloid Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2212-2212
Author(s):  
Eric O'Brien ◽  
Brett VanCauwenbergh ◽  
Luke Byerly ◽  
Alexander Merk ◽  
Mayur Sarangdhar ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
Myeloid Leukemia ◽  
Drug Sensitivity ◽  
Cell Function ◽  
Ex Vivo ◽  
In Vitro Drug Screening ◽  
Pediatric Aml ◽  
Acute Myeloid

Abstract Each case of Acute Myeloid Leukemia (AML) represents a unique ecosystem. Despite recent advances in our understanding of the genetic landscape of AML, this information remains insufficient to accurately match patients with targeted therapies. While pediatric and adult AML share phenotypic similarities, pediatric AML represents a genetically distinct disease from adult AML, and will benefit from independent genomic studies and novel therapeutic strategies. Real-time ex-vivo functional screening can identify mechanisms underpinning drug response and diversity between tumors, aiding in patient stratification. We established an in vitro drug screening system that incorporates cytokine signaling to better model inflammation, stem cell function, and niche derived support of leukemic blasts. This approach provided insight into variability between patients who currently would be placed on the same therapeutic regimen. Samples were acquired from 12 pediatric AML patients, after informed consent was obtained. Samples were enriched for blasts, and cultured in the presence of SCF, TPO, FLT3-L, IL-3, and IL-6 (KTF36). A panel of 38 drugs was selected from a larger screen of 1839 compounds done on commercially available hematological malignancy cell lines. Drugs included standard chemotherapy agents used in AML and drugs currently under clinical development. Cells were exposed to drugs for 72hrs. An MTS assay was performed and results reported as % of viable cells remaining, after normalization to vehicle control wells. Targeted DNA NGS sequencing of 406 genes, 31 introns, and RNA sequencing of 265 genes was performed for genetic characterization. In vitro drug screening revealed variations in drug sensitivity between samples and revealed time ex-vivo and cytokine milieu to be important factors affecting response of the same cells to the same drugs. Engraftment of long term cultures into immunodeficient mice produced aggressive disease in all cases, indicating robust support of stem cell function via addition of KTF36 cytokines. When possible, clinical response to therapy was compared with in vitro response to the same drugs. This screening approach highlighted well established agents that showed significant activity in highly refractory disease providing rationale for further clinical trial development. An unsupervised clustering showed drug sensitivity primarily correlated with the presence of MLL-X fusion, NRAS/KRAS and PTPN11 alterations. Linear Regression with interaction effects showed drug sensitivity/resistance to be highly selective for single/signature of specific molecular alterations. Figure. Figure. Disclosures No relevant conflicts of interest to declare.

scholarly journals Long-term leukemia-initiating capacity of a CD34-subpopulation of acute myeloid leukemia

Blood ◽  
1996 ◽  
Vol 87 (6) ◽  
pp. 2187-2194 ◽  
Author(s):  
W Terpstra ◽  
A Prins ◽  
RE Ploemacher ◽  
BW Wognum ◽  
G Wagemaker ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Scid Mice ◽  
Cell Compartments ◽  
Cd34 Cells ◽  
Normal Cytogenetics ◽  
Acute Myeloid

Acute myeloid leukemia (AML) proliferation in vivo is maintained by a small fraction of progenitor cells. These cells have been assumed to express an immature phenotype and to produce most colony-forming units (CFU-AML). For one case of AML (French-American-British [FAB] M1, normal cytogenetics), we examined the capacity of the CD34+ (25% of unseparated AML cells) and CD34- fractions to initiate leukemia in severe combined immunodeficient (SCID) mice. In addition, the production of CFU-AML and nucleated cells (NC) of these subsets was investigated in long-term bone marrow culture (LTBMC). The frequencies of cobblestone area-forming cells (CAFC) were also estimated; early appearing cobblestone areas (CAs) are indicative of relatively mature progenitors and late CAs represent the progeny of primitive progenitors. In mice transplanted with CD34- (98% pure) or CD34+ (98% pure) grafts, similar AML cell growth was seen throughout an observation period of 106 days. The capacity to establish long-term growth from the CD34- cells was confirmed by renewed outgrowth after retransplantation. In vitro, the CD34- fraction contained both immature and mature CAFCs and produced high numbers of CFU-AML and NC in LTBMC. The CD34+ fraction produced only small numbers of CFU-AML, NC, and mature CAFCs. Therefore, the expression of CD34 and the content of CFU- AML were not associated with long-term growth of AML. However, similar frequencies of primitive CAFCs were observed in both fractions. Thus, both CD34- and CD34+ subsets of this AML sample contained immature progenitors with the capacity to initiate long-term AML growth as characterized in vivo (in SCID mice) as well as in vitro (in CAFC assay), indicating asynchrony between functional and immunophenotypical maturation of AML progenitor cell compartments.

Autologous Stem Cell Transplantation in Patients of High and Intermediate Risk Acute Myeloid Leukemia:-Perspective of a Developing Country.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4364-4364
Author(s):  
Velu Nair ◽  
Satyaranjan Das ◽  
Sanjeevan Sharma ◽  
Ajay Sharma ◽  
Deepak Kumar Mishra ◽  
...  
Keyword(s):  
Stem Cell ◽  
Myeloid Leukemia ◽  
Intermediate Risk ◽  
Trisomy 8 ◽  
Leukemia Relapse ◽  
Normal Cytogenetics ◽  
Matched Donor ◽  
Related Mortality ◽  
Acute Myeloid

Abstract Abstract 4364 Introduction Most patients with acute myeloid leukemia (AML) who achieve a complete remission after induction chemotherapy will relapse if they do not receive effective consolidation therapy particularly patients of high and intermediate risk. Standard chemotherapy only achieves less than 30% overall survival at 2 years. The most effective consolidation for high risk and intermediate risk patients is allogeneic stem cell transplantation (allo-SCT) which may be related or unrelated. However in the developing world availability of a human leucocyte antigen (HLA) matched donor for those lacking a sibling match is rarely available due to minority of voluntary donors from Indian subcontinent in various registries. Hence autologous stem cell transplant (auto-SCT) is one option that has been studied extensively. The question as to whether auto-SCT after consolidation chemotherapy improves the probability of survival of patients with AML has not been settled. In view of the above considerations, we carried out a retrospective study aimed at analyzing the impact of disease, patient, and transplantation-related factors on relapse, non–leukemia-related death, and LFS of patients with AML. Patients and methods We present here retrospective data of 16 patients of AML who undergone auto SCT in our centre from Jan 2005 to Jan 2009. The median age of patients was 24 yrs with a range from 10 to 40 years. Male: Female ratio was 11:5. The diagnosis was established on both bone marrow morphology and immunophenotyping study. Morphologically there was 1 case each of AML-M1, AML-M4, AML-M5, AML-M6 and rest 13 cases were of AML-M2. Bone marrow karyotyping was done in 11 cases. Out of 11 cases where karyotyping was done, 2 were metaphase failures; 1 was deletion 7; 1 was trisomy 8 and rest had normal cytogenetics. All cases were classified as high risk or intermediate risk either by cytogenetics or by other standard criteria. All patients received standard induction chemotherapy (Idarubicin x 3days, Cytosine CI x 7days) followed by 2 or 3 high dose Cytosine. Fourteen patients were in first remission (CR-1) while 2 patients were in CR-2 (one case of AML-M5 with deletion 7 and one AML-M4 with normal cytogenetics). None of the patients had a related HLA matched donor and all patients underwent auto-SCT, the graft being peripheral blood stem cell. The conditioning regimen for initial 6 cases were Busulfan(16mg/kg over 4 days) and Cyclophosphamide(120mg/kg over 2 days)(BuCy) and the remaining 10 cases were adminstered Idarubicin (60mg/mt2 over 3days) and Busulfan (16mg/kg over 4 days) (IBu). All cases engrafted except one patient who died due to sepsis on 6th day post SCT prior to engraftment. The median engraftment for neutrophil was day10 (9-14) and platelet was on day 16 (13 - 20). Results Nine out of 16 patients are alive and free from leukemia on median follow up of 38 (18 to 56 months). Five patients died due to leukemia relapse; 1 patient had transplant related mortality (Sepsis) and 1 patient died due to unrelated cause (Severe heat exertion with multiorgan failure). The overall (OS) and leukemia free survival (LFS) on a median follow up of 38 months was 56.25% which is better than the chemotherapy group. The treatment related mortality (TRM) was 6.25%. Both patients transplanted in CR-2 relapsed and died. Three out of 6 patients from BuCy and 6 out 10 from IBu conditioning are alive. Out of 9 patients surviving, 5 had normal karyotype while in 4 same was not known. The patients with deletion 7 and trisomy 8 died due to leukemia relapse. Conclusion Auto-SCT is a viable option for AML patients who are in need of a allo-SCT but do not have a donor. However larger studies would be required to establish the exact role of auto-SCT in AML. Disclosures: No relevant conflicts of interest to declare.

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