Early Stem Cell Transplantation for Refractory Acute Leukemia after Salvage Therapy with High-Dose Etoposide and Cyclophosphamide

AbstractPrimary refractory acute leukemia (AL) has a poor prognosis, although some patients can be salvaged with allogeneic stem cell transplantation (SCT). Induction of complete remission (CR) with conventional chemotherapy before SCT may improve outcome in this patient population. Between March 1991 and October 2003, 59 adults with primary refractory AL were treated with continuous-infusion etoposide (VP) 2.4 to 3.0 g/m2 followed by cyclophosphamide (Cy) 6.0-7.2 g/m2 intravenously over 3 to 4 days with the intention of proceeding to SCT in CR1. Forty-two patients had acute myelogenous leukemia (AML), 13 patients had acute lymphoblastic leukemia (ALL), and 4 patients had acute biphenotypic leukemia. The most frequent nonhematologic toxicities were oral mucosal, gastrointestinal, and hepatic toxicities (44%, 20%, and 15% of patients, respectively). Thirty-two (57%) of 56 evaluable patients entered CR1 with a median time to platelet and neutrophil recovery of 22 and 26 days, respectively. CR1 rates were similar in AML (54%) and ALL/acute biphenotypic leukemia (67%; P = .52), and analysis of baseline characteristics did not reveal any predictors of response to VP/Cy. Twenty-nine of 32 CR1 patients subsequently underwent SCT (24 allogeneic and 5 autologous). Estimated 5-year event-free survival (EFS) and overall survival for the entire cohort are 23% and 26%, respectively. In the allogeneic SCT group, 5-year EFS was 52% for AML patients and 14% for ALL patients (P = .04), and only male sex was predictive of a favorable outcome (P = .03). VP/Cy is able to induce CR1 in most patients with primary refractory AL with an acceptable toxicity profile. Subsequent allogeneic SCT can lead to long-term EFS in a significant proportion of patients

Influence of cytogenetic abnormalities on outcome after allogeneic bone marrow transplantation for acute myeloid leukemia in first complete remission

AbstractCytogenetic abnormalities detected at diagnosis are recognized as important in predicting response to chemotherapy in acute myeloid leukemia (AML). However, there is controversy concerning the prognostic significance of karyotype for outcome after allogeneic bone marrow transplantation (allo-BMT) performed in first complete remission (CR1). This single-institution report describes allo-BMT for AML in CR1 and the effect of diagnostic cytogenetic findings on the results of that treatment. Between August 1981 and December 1999, 93 patients underwent related donor (n = 82) or unrelated donor (n = 11) BMT. Conditioning and GVHD prophylaxis were achieved predominantly with busulfan and cyclophosphamide and with cyclosporine and methotrexate, respectively. Seventy-nine (85%) of 93 patients had successful marrow karyotyping at diagnosis, and the patients were categorized into 3 prognostic groups based on the British Medical Research Council AML 10 trial classification: 15 patients(19%) were classified as having favorable risk [inv(16), t(8;2 1), t(15;17)]; 55 (70%) as having intermediate risk [no abnormality, +8, +21, +22, del(7q), del(9q), 11q23 rearrangement, and other numerical or structural abnormalities]; and 9 (11%) as having adverse risk [-5, del(5q), -7, 3q rearrangements, > or = 5 abnormalities, t(6;9), t(9;22)]. The median follow-up was 93 months (range, 16-241 months). The overall survival (OS) rate, event-free survival (EFS) rate, relapse rate, and treatment-related mortality (TRM) were not statistically different between the groups. The 5-year actuarial EFS rates for favorable, intermediate, and adverse risk groups were 58% (95% confidence interval [CI], 29%-79%), 58% (95% CI, 43%-70%), and 67% (95% CI 28%-88%), respectively. Reclassification of patients into cytogenetic prognostic subgroups according to Southwest Oncology Group criteria did not change these results. In univariate analysis, the only variable found to have a prognostic influence on OS (P = .04) and TRM (P = .03) was the type of donor (unrelated donor was linked to a worse prognosis), which was confirmed in multivariate analysis. Our study suggests that presentation karyotype has less prognostic significance for outcome following allo-BMT than for outcome following conventional chemotherapy. In particular, AML patients with poor prognostic cytogenetic changes in CR1 who are unlikely to be cured with chemotherapy alone may benefit from allo-BMT.Biol Blood Marrow Transplant 2002;8(8):435-43

Phase 2 trial of CPX-351, a fixed 5:1 molar ratio of cytarabine/daunorubicin, vs cytarabine/daunorubicin in older adults with untreated AML

CPX-351 is a liposomal formulation of cytarabine: daunorubicin designed to deliver synergistic drug ratios to leukemia cells. In this phase 2 study, newly diagnosed older acute myeloid leukemia (AML) patients were randomized 2: 1 to first-line CPX-351 or 713 treatment. The goal was to determine efficacy and identify patient subgroups that may benefit from CPX-351 treatment. Response rate (complete remission 1 incomplete remission) was the primary end point, with event-free survival (EFS) and overall survival (OS) as secondary end points. The 126 patients entered were balanced for disease and patient-specific risk factors. Overall, CPX-351 produced higher response rates (66.7% vs 51.2%, P = .07), meeting predefined criteria for success (P \u3c .1). Differences in EFS and OS were not statistically significant. A planned analysis of the secondary AML subgroup demonstrated an improved response rate (57.6% vs 31.6%, P = .06), and prolongation of EFS (hazard ratio [HR] = 0.59, P = .08) and OS (HR = 0.46, P = .01). Recovery from cytopenias was slower after CPX-351 (median days to absolute neutrophil count \u3e= 1000: 36 vs 32; platelets \u3e100 000:37 vs 28) with more grade 3-4 infections but without increase in infection-related deaths (3.5% vs 7.3%) or 60-day mortality (4.7% vs 14.6%), indicating acceptable safety. These results suggest a clinical benefit with CPX-351, particularly among patients with secondary AML, and provide the rationale for a phase 3 trial currently underway in newly diagnosed secondary AML patients. This study is registered at Clinicaltrials.gov as #NCT00788892

Quality of Life and Socioeconomic Indicators Associated with Survival of Myeloid Leukemias in Canada

Understanding how patient‐reported quality of life (QoL) and socioeconomic status (SES) relate to survival of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) may improve prognostic information sharing. This study explores associations among QoL, SES, and survival through administration of the Euro‐QoL 5‐Dimension, 3‐level and Functional Assessment of Cancer Therapy‐Leukemia and financial impact questionnaires to 138 adult participants with newly diagnosed AML or MDS in a longitudinal, pan‐Canadian study. Cox regression and lasso variable selection models were used to explore associations among QoL, SES, and established predictors of survival. Secondary outcomes were changes in QoL, performance of the QoL instruments, and lost income. We found that higher QoL and SES were positively associated with survival. The Lasso model selected the visual analog scale of the EQ‐5D‐3L as the most important predictor among all other variables (P = .03; 92% selection). Patients with AML report improved QoL after treatment, despite higher mean out‐of‐pocket expenditures compared with MDS (up to $599 CDN/month for AML vs$239 for MDS; P = .05), greater loss of productivity‐related income (reaching id="mce_marker"786/month for AML vs $709 for MDS; P < .05), and greater caregiver effects (65% vs 35% caregiver productivity losses for AML vs MDS; P < .05). Our results suggest that including patient‐reported QoL and socioeconomic indicators can improve the accuracy of survival models

Genetic investigations of human hemopoiesis : studies of clonality and gene transfer to hemopoietic progenitors

In most neoplasms malignant change occurs in a single cell which then proliferates. My purpose was to explore methods to study the cell that gives rise to hemopoietic cancer and to investigate the abnormalities at a molecular level. Cytogenetic analysis of cells from individual hemopoietic colonies revealed that monosomy 7 syndrome, a hematologic disorder of childhood, arises in a primitive cell capable of differentiating down both myeloid and erythroid pathways. Long-term bone marrow cultures (LTC) from patients with chronic myelogenous leukemia (CML) favor the growth of Philadelphia chromosome (Ph) negative progenitors which, although cytogenetically normal, could have been part of the malignant clone at a stage prior to the development of the Ph. LTC's were initiated with cells from 2 women with CML who were heterozygous for 2 electrophoretically distinct glucose-6-phosphate dehydrogenase (G6PD) enzyme variants. In one patient, 2/11 progenitors were Ph-negative after 4 to 6 weeks in LTC and 4/30 were nonclonal by G6PD enzyme analysis, i.e. the colonies expressed the enzyme not found in the malignant clone. In this case, karyotypically normal cells were truly normal. Next, gene transfer to human hemopoietic cells was demonstrated using recombinant retrovirus carrying the selectable marker gene, neor. With the K562 human leukemic cell line as targets up to 60% of infected cells became G418 resistant (G418r). Cloned populations of G418r cells showed unique patterns of retroviral integration in K562 DNA. When the target cells were progenitors from normal marrow, CML blood or fetal liver, the highest frequencies of G418r granulocyte-macrophage or large erythroid colonies was 16% and 5% respectively. Experiments infecting bone marrow cells in LTC with neor virus produced up to 2% G418r colonies after as long as 3 weeks in culture. Using v-src virus to infect LTC failed to perturb hemopoiesis, although infection of bone marrow-derived cells in these cultures was documented. In summary: 1. Unique populations of hemopoietic progenitors can be identified in culture using several genetic markers including chromosomes, G6PD analysis or gene transfer. 2. The feasibility of retroviral-mediated gene transfer for use on human hemopoietic cells has been demonstrated.Medicine, Faculty ofPathology and Laboratory Medicine, Department ofGraduat

Expression of Integrin A2 Receptor in Human Cord Blood Cd34+Cd38-Cd90+ Stem Cells Engrafting Long-Term in Nod/Scid-Il2rγ(C) Null Mice.

Human hematopoietic stem cells reside in the CD34+CD38-CD90+ population in cord blood and bone marrow. However, this cell fraction is heterogeneous, and the phenotype of the rare primitive stem cells remains poorly defined. We here report that primitive cord blood CD34+CD38-CD90+ stem cells, with the ability to reconstitute NOD/SCID-IL2Rγ(c) null mice long term, at 24 weeks after transplantation, can be prospectively isolated at an increased purity by using integrin α2 receptor as an additional stem cell marker. Using a limiting dilution transplantation assay, we found a highly significant enrichment of multilineage reconstituting stem cells in the CD34+CD38-CD90+ cell fraction expressing the integrin α2 receptor, with a frequency of 1/29 cells, as compared to a frequency of 1/157 in the corresponding integrin α2- cells. In line with this, long-term reconstituting stem cells within the cord blood CD34+CD38- cell population were significantly enriched in the integrin α2+ fraction, while stem cells and progenitors reconstituting short-term, at 8-12 weeks, were heterogeneous in integrin α2 expression. Global gene expression profiling revealed that the lineage-marker negative (Lin-) CD34+CD38-CD90+CD45RA- integrin α2+ cell population was molecularly distinct from the integrin α2- cell population and the more mature Lin-CD34+CD38-CD90-CD45RA- cell population. Our findings identify integrin α2 as a novel stem cell marker, which improves prospective isolation of the primitive human hematopoietic stem cells within the CD34+CD38-CD90+ cell population for experimental and therapeutic stem cell applications

Economic impact of genomic diagnostics for intermediate‐risk acute myeloid leukaemia

Acute Myeloid Leukaemia (AML) is a rare but serious group of diseases that require critical decision‐making for curative treatment. Over the past decade, scientific discovery has revealed dozens of prognostic gene mutations for AML while sequencing costs have plummeted. In this study, we compared the cost‐effectiveness of multigene integrative analysis (genomic analysis) with the standard molecular testing currently used for diagnosis of intermediate‐risk AML. We used a decision analytic model with data for costs and outcomes from British Columbia, Canada, to assess the long‐term (10‐year) economic impacts. Our results suggest that genomic analysis would result in a 26% increase in the use of first‐remission allogeneic stem cell transplantation. The resulting treatment decisions and downstream effects would come at an additional cost of $12 556 [2013 Canadian dollars (CAD)] per person and the incremental cost‐effectiveness ratio would be$49 493 per quality‐adjusted life‐year gained. Cost‐effectiveness was dependent on quality of life during the long‐term (5–10) years of survival, relapse rates following first‐remission chemotherapy and the upfront cost of transplantation. Non‐relapse mortality rates, short‐term quality of life and the cost of genomic sequencing had only minor impacts. Further research on post‐remission outcomes can lead to improvements in the cost‐effectiveness of curative treatments for AML

Fotografia B221

The front-line treatment for adult acute myeloid leukemia (AML) is anthracycline-based combination chemotherapy. However, treatment outcomes remain suboptimal with relapses frequently observed. Among the mechanisms of treatment failure is multidrug resistance (MDR) mediated by the ABCB1, ABCC1, and ABCG2 drug-efflux transporters. Although genetic and phenotypic heterogeneity between leukemic blast cells is a well-recognized phenomenon, there remains minimal data on differences in MDR activity at the individual cell level. Specifically, functional assays that can distinguish the variability in MDR activity between individual leukemic blasts are lacking. Here, we outline a new dielectrophoretic (DEP) chip-based assay. This assay permits measurement of drug accumulation in single cells, termed same-single-cell analysis in the accumulation mode (<i>SASCA-A</i>). Initially, the assay was optimized in pretherapy samples from 20 adults with AML whose leukemic blasts had MDR activity against the anthracyline daunorubicin (DNR) tested using multiple MDR inhibitors. Parameters tested were initial drug accumulation, time to achieve signal saturation, fold-increase of DNR accumulation with MDR inhibition, ease of cell trapping, and ease of maintaining the trapped cells stationary. This enabled categorization into leukemic blast cells with MDR activity (MDR⁺) and leukemic blast cells without MDR activity (MDR^–ve). Leukemic blasts could also be distinguished from benign white blood cells (notably these also lacked MDR activity). MDR^–ve blasts were observed to be enriched in samples taken from patients who went on to enter complete remission (CR), whereas MDR⁺ blasts were frequently observed in patients who failed to achieve CR following front-line chemotherapy. However, pronounced variability in functional MDR activity between leukemic blasts was observed, with MDR⁺ cells not infrequently seen in some patients that went on to achieve CR. Next, we tested MDR activity in two paired AML patient samples. Pretherapy samples taken from patients that achieved CR to front-line chemotherapy were compared with samples taken at time of subsequent relapse. MDR⁺ cells were frequently observed in leukemic blast cells in both pretherapy and relapsed samples, consistent with MDR as a mechanism of relapse in these patients. We demonstrate the ability of a new DEP microfluidic chip-based assay to identify heterogeneity in MDR activity in leukemic blasts. The test provides a platform for future studies to characterize the mechanistic basis for heterogeneity in MDR activity at the individual cell level