2-Chlorodeoxyadenosine with or without daunorubicin in relapsed or refractory acute myeloid leukemia

 2-Chlorodeoxyadenosine (2-CdA) is a purine analogue which has proved to be active in acute myeloid leukemia (AML), especially in children. In adults, results yielded by 2-CdA alone or with ara-C were less encouraging. Here we report on the efficacy of 2-CdA with or without daunorubicin (DNR) in 19 relapsing or refractory adult AML patients, with a median age of 57 years. 2-CdA was administered as a continuous infusion to all patients at a dose of 0.1 mg/kg per day for 7 days. For 14 patients, DNR was added at a dose of 50 mg/m² per day on days 5, 6, and 7. Antileukemic activity was observed in all the patients, but no single complete remission was achieved. One patient had a long-lasting partial response (response rate=5%). The remaining patients died of progressive AML (n=7), uncontrollable infection with persistent disease (n=10), and cerebral hemorrhage (n=1). Median survival from start of 2-CdA therapy was 56 days. Long-lasting neutropenia and transfusion-dependent thrombopenia were encountered in all 16 evaluable patients. Grade 4 hepatic toxicity occurred in one patient. Other side effects included nausea in six, mucositis in three, and mental disturbances in three patients. Compared with 2-CdA alone, the addition of DNR to 2-CdA changed neither the response rate nor the toxicities. In conclusion, our data do not support the use of 2-CdA ± DNR for relapsing or refractory adult AML patients, at least as used in the present regimen. Received: 21 July 1997 / Accepted: 18 November 1997     

Novel strategies for relapsed and refractory acute myeloid leukemia

PURPOSE OF REVIEW: Treatment for relapsed or refractory acute myeloid leukemia remains a major challenge for the leukemia community. Although several approaches have been tested in phase II study designs, few comparative data exist to guide treatment choices. We searched the recent literature in Medline, EMBASE and BIOSIS, and abstracts from the American Society of Hematology and American Society of Clinical Oncology published between 2005 and 2007. We reviewed each report to identify studies that used a phase II or III design and that included a majority of adults with non-M3 acute myeloid leukemia described as 'relapsed' or 'refractory'. RECENT FINDINGS: Several studies utilized novel cytotoxic chemotherapies, immunotherapies, epigenetic agents, and small molecule inhibitors. It is not possible to identify a single regimen or approach as the standard of care in relapsed and refractory acute myeloid leukemia. New and promising approaches are being explored, however. SUMMARY: Outcomes in patients treated for relapsed or refractory acute myeloid leukemia remain inadequate. Striking a balance between the treatment-related mortality associated with salvage therapies, response rates of salvage regimens, and the likelihood of long-term disease-free survival are critical in planning a treatment approach for the individual patient with relapsed or refractory acute myeloid leukemia.     

Treatment of relapsed or refractory acute promyelocytic leukemia

Current treatment for acute promyelocytic leukemia (APL) usually includes an induction phase with all-trans retinoic acid (ATRA) and anthracycline-based chemotherapy, followed by a consolidation phase of anthracycline-based chemotherapy and maintenance therapy with ATRA with or without low-dose chemotherapy for 1-2 years. This treatment strategy results in a high complete remission (CR) rate of about 90% and an overall survival rate of 80%. About 5%-30% of patients relapse, mainly patients with high-risk APL. Relapse at extramedullary sites, which occurs in approximately 3%-5% of patients, is emerging as a new issue. Treatment of relapsed/advanced APL includes the use of arsenic trioxide (ATO), gemtuzumab ozogamicin, and hematopoietic stem cell transplantation. ATO is currently the most effective therapeutic agent in relapsed APL. Hematopoietic stem cell transplantation is becoming a common strategy after achieving remission with ATO. Autologous transplant appears to have a more favorable outcome than allogeneic transplant in this setting, particularly when carried out during second remission, primarily because of significantly higher treatment-related mortality with allogeneic transplants. Allogeneic transplant, however, should be strongly considered for patients who remain molecularly positive. Future directions for APL therapy should include developing agents that can prevent relapse, particularly for high-risk patients. Other future treatment strategies may include use of ATO administered concomitantly or sequentially with chemotherapy, gemtuzumab or FLT-3 inhibitors that may obviate the need for autologous transplantation, and posttransplant maintenance perhaps with FLT-3 inhibitors.     

Progress and strategies for patients with relapsed and refractory acute myeloid leukemia

PURPOSE OF REVIEW: The treatment of patients with refractory or relapsed acute myeloid leukemia remains challenging. Management of these patients must take into account patient and leukemia-related factors in order to organize a comprehensive approach to treatment. Many new therapies are under study. RECENT FINDINGS: New molecular markers that represent mutations or gene overexpression have been identified including FMS-like tyrosine kinase-3 and nucleophosmin, which will enhance our ability to more accurately prognosticate for patients with acute myeloid leukemia. Monoclonal antibodies and peptide vaccination with leukemia-associated antigens bring the hope of increasing the remission and cure rates for patients with acute myeloid leukemia. The use of reduced-intensity conditioning blood or marrow transplantation is finding a broader role in the treatment of acute myeloid leukemia. SUMMARY: Patients with relapsed or refractory acute myeloid leukemia should be entered on clinical trials whenever feasible given the lack of consensus on the most effective treatment in this setting. Blood and marrow transplantation remains the only known curative therapy for these patients and the use of reduced-intensity conditioning blood or marrow transplantation offers the option of this approach to older and more infirm patients. Greater understanding of the biology of acute myeloid leukemia will provide new molecular targets of use in diagnosis, monitoring, and for the development of new, targeted therapies.     

5‐Azacytidine treatment for relapsed or refractory acute myeloid leukemia after intensive chemotherapy

Despite progress in the understanding of leukemia pathophysiology, the treatment of acute myeloid leukemia (AML) remains challenging. In patients with refractory or relapsed (R/R) AML, the prognosis is still poor and this group is targeted for new drug development. We reviewed the outcome of 47 patients, with R/R AML after at least one course of intensive chemotherapy, treated with 5‐azacytidine in three different French institutions. The overall response rate was 38% including complete remission in 21%, partial remission in 11%, and hematological improvement in 6% of cases. Median time to relapse was 6 (range, 1–39) months. Median overall survival was 9 months (not reached by responders vs. 4.5 months for nonresponders patients, P = 0.0001). Univariate analysis identified the absence of peripheral blood blasts and <20% bone marrow blasts as prognostic factors for both overall response and survival, but not age, ECOG/PS, type of AML, cytogenetic, status of the disease, number of previous lines of therapy, previous hematological stem cell transplantation, or white blood cells count. Bone marrow blasts percentage <20% was the only independent prognostic factor identified by multivariate analysis for overall response (P = 0.0013) and survival (P = 0.0324). Six patients in remission could proceed to an allogenic hematological stem cell transplantation. The drug‐related grade 3/4 adverse events were hematopoietic toxicities (38%) and infection (32%). In conclusion, this study suggests that a salvage therapy with 5‐azacytidine is an interesting option for patients with R/R AML after intensive chemotherapy. Prospective randomized studies are needed to demonstrate a superiority of this approach over others strategies. Am. J. Hematol. 88:601–605, 2013. © 2013 Wiley Periodicals, Inc.     

联合定量检测急性髓系白血病患者MDR1和WT1基因表达及临床意义

目的 联合定量检测初治急性髓系白血病(AML)患者MDR1及WT1基因的表达水平,探讨MDR1与WT1的表达量在AML耐药中作用及相互关系.方法 构建实时荧光定量PCR检测WT1和MDR1基因表达水平技术,并检测63例初治AML患者WT1和MDR1基因的表达量及与临床疗效的关系.结果 63例初治AML患者MDRI基因表达(拷贝/μg RNA)的中位数为2863(413～3 410 000),WT1基因表达为52 700(7731～1 020 000).10例正常对照组MDR1和WT1基因表达水平为337(125～840)和849(635～1402).初治AML患者MDR1和WT1基因表达水平均显著高于正常对照组(P＜0.001).且MDR1与WT1基因表达水平呈相关性(P=0.004);FAB各亚型中MDR1和WT1基因表达水平差异无统计学意义(P＞0.05);遗传学危险度分级的高、中、低危3组的WT1和MDR1基因表达水平差异无统计学意义(P＞0.05).FLT3-ITD突变阳性组MDR1基因表达水平与突变阴性组相比差异无统计学意义(P＞0.05).FLT3-ITD突变阳性组的WT1基因表达水平显著高于阴性组(P＜0.05).AML患者中WT1和MDR1基因共同高表达组完全缓解率显著低于共同低表达组(P＜0.05).结论 AML患者MDR1和WT1基因表达水平存在相关性;联合检测AML患者MDR1和WT1基因表达量更能早期预测预后.     

Clinical relevance of P-glycoprotein expression in de novo acute myeloid leukemia

Cytofluorimetric detection of the multidrug resistance (MDR)-associated membrane protein (P-170) was performed at the time of diagnosis in 158 patients with acute myeloid leukemia using the C219 monoclonal antibody (MoAb). In 108 of these cases the JSB1 MoAb was also tested. An improved histogram subtraction analysis, based on curve fitting and statistical test was applied to distinguish antigen-positive from antigen-negative cells. A marker was considered positive when more than 20% of the cells were stained. At onset, P-170 was detected in 43% of cases with C219 and in 73% of cases with JSB1. There was a strict correlation between C219 and JSB1 positivity, as all C219+ cases were also positive for JSB1 MoAb (P < .001). No relationship was found between sex, age, organomegaly, and MDR phenotype. Significant correlation was found between CD7 and both C219 and JSB1 expression (P < .001 and .001, respectively). C219-negative phenotype was more often associated with a normal karyotype (24 of 55 with P = .030). Rhodamine 123 (Rh123) staining and flow cytometry analysis showed a significantly decreased mean fluorescence in 51 C219+ and 38 JSB1+ patients compared to 42 MDR negative ones (P < .001). The rate of first complete remission (CR) differed both between C219+ and C219- cases and between JSB+ and JSB- ones (30.9% v 71.1% and 35.4% v 93.1%, respectively, P < .001). Of the 21 C219+ patients who had yielded a first CR, 19 (90.4%) relapsed, compared with 28 of 64 (43.7%) C219- patients (P < .001). Of the 28 JSB1+ patients in first CR, 17 (60.7%) relapsed relative to 8 (29.6%) of 27 JSBI- ones (P = .021). A higher rate of relapses among MDR+ compared with MDR- patients was observed both for C219 and JSB1 MoAbs taken separately (C219 80% v 44%; JSB1 52% v 27%), with no relationship to age. The survival rates (Kaplan-Meyer method) were significantly shorter both in C219+ patients and in JSB1+ cases (P < .001). Disease-free survival curves followed this same trend. The combination (C219- JSB1+) identified a subset of patients with an intermediate outcome compared to C219 positive cases. The prognostic value of both markers (C219 and JSB1) was confirmed in multivariate analysis. These results suggest that the assessment of MDR phenotype by flow cytometry may be an important predictor of treatment outcome.     

Single agent thalidomide in patients with relapsed or refractory acute myeloid leukaemia

Thalidomide is a putative anti-angiogenesis agent that has significant anti-tumour activity in haematological malignancies with increased bone marrow angiogenesis, including multiple myeloma (MM) and myelodysplastic syndromes (MDS). Increased levels of the mitogen for angiogenesis, vascular endothelial growth factor (VEGF), correlate with worse survival in acute myeloid leukaemia (AML). A phase II trial of thalidomide was conducted in patients with relapsed- or refractory-AML previously treated with cytarabine-containing regimens. A total of 16 patients with refractory- or relapsed-AML were treated with thalidomide 200-800 mg orally daily (median dose 400 mg daily) for a median of 27 d (range, 3-94 d). Overall, one patient (6%) achieved complete remission (CR) lasting for 36 months, and two patients had a transient reduction in marrow blasts from 8% and 7% to less than 5% in both cases. There was no correlation between reduction in levels of angiogenesis markers and response. Toxicities related to thalidomide were significant, and precluded dose escalation beyond 400 mg orally daily in most patients. Although there appears to be some evidence of biological activity, single agent thalidomide is not an optimal choice of therapy for salvaging patients with relapsed- or refractory-AML. Thalidomide analogues with more potent immunomodulatory activities and more favourable toxicity profiles may offer more promise as anti-AML therapy.     

Allogeneic hematopoietic cell transplantation with reduced-intensity conditioning following FLAMSA for primary refractory or relapsed acute myeloid leukemia

Patients with primary refractory or relapsed acute myeloid leukemia (AML) have a dismal prognosis. We report a retrospective single center analysis of aplasia-inducing chemotherapy using fludarabine, cytarabine, and amsacrine (FLAMSA) followed by reduced-intensity conditioning (RIC) for allogeneic hematopoietic cell transplantation (HCT) in 62 consecutive primary refractory or relapsed AML patients. Two-year event-free survival and overall survival (OS) were 26 and 39 %, respectively. Risk stratification according to cytogenetic and molecular genetic markers showed superior survival in patients in the intermediate-1 risk group (2-year OS 70 %) compared to the intermediate-2 risk (2-year OS 34 %, p?=?0.03) and adverse risk (2-year OS 38 %, p?=?0.06) group. The use of HLA-matched versus HLA-mismatched donors had no significant influence on survival (p?=?0.98). Two-year OS in the elderly subgroup defined by age ≥60 years was 31 % compared to 46 % in the group of younger patients <60 years (p?=?0.19). Cumulative incidence of non-relapse mortality at 2 years adjusted for relapse as competing risk was 20 % for patients <60 years and 26 % for older patients (p?=?0.55). Chronic graft-versus-host disease was associated with a statistically significant superior survival (p?<?0.01). FLAMSA-RIC followed by allogeneic HCT enables long-term disease-free survival in primary refractory or relapsed AML even in the elderly patient population.     

A phase 1/2 study of chemosensitization with the CXCR4 antagonist plerixafor in relapsed or refractory acute myeloid leukemia

The interaction of acute myeloid leukemia (AML) blasts with the leukemic microenvironment is postulated to be an important mediator of resistance to chemotherapy and disease relapse. We hypothesized that inhibition of the CXCR4/CXCL12 axis by the small molecule inhibitor, plerixafor, would disrupt the interaction of leukemic blasts with the environment and increase the sensitivity of AML blasts to chemotherapy. In this phase 1/2 study, 52 patients with relapsed or refractory AML were treated with plerixafor in combination with mitoxantrone, etoposide, and cytarabine. In phase 1, plerixafor was escalated to a maximum of 0.24 mg/kg/d without any dose-limiting toxicities. In phase 2, 46 patients were treated with plerixafor 0.24 mg/kg/d in combination with chemotherapy with an overall complete remission and complete remission with incomplete blood count recovery rate (CR + CRi) of 46%. Correlative studies demonstrated a 2-fold mobilization in leukemic blasts into the peripheral circulation. No evidence of symptomatic hyperleukocytosis or delayed count recovery was observed with the addition of plerixafor. We conclude that the addition of plerixafor to cytotoxic chemotherapy is feasible in AML, and results in encouraging rates of remission with correlative studies demonstrating in vivo evidence of disruption of the CXCR4/CXCL12 axis.     

Semiquantitative RT-PCR evaluation of the MDR1 gene expression in patients with acute myeloid leukemia

Resistance to chemotherapy is one of the major obstacles to effective treatment in acute myeloid leukemia (AML). The most extensively studied protein involved in multidrug resistance (MDR) is the transmembrane glycoprotein P (P-gp), the product of the multidrug resistance gene 1 (MDR1). MDR1/P-gp overexpression is frequently observed in hematological malignancies, especially in acute leukemia, and has been reported to correlate with poor prognosis in acute myeloid leukemia (AML). The aim of this study was to evaluate the level of MDR1 gene expression in bone marrow and/or peripheral blood samples in 92 AML patients in relation to their prognosis. The analyzed group was stratified according to presence or absence of prognostically favorable aberrations (PFAs), such as t(15;17) with PML/RARalpha fusion gene, t(8;21) with AML1/ETO fusion gene or inv(16)/ t(16;16) with CBFbeta/MYH11 fusion gene. These prognostically favorable aberrations were detected by RT-PCR and/or standard cytogenetic techniques. MDR1 expression was detected by semiquantitative comparative RT-PCR using software-based evaluation. The levels of MDR1 expression in the bone marrow predicted induction of complete remission in the whole group of analyzed patients (P = 0.032). They were significantly lower in PFA negative patients who achieved complete remission compared to those who failed to achieve complete remission (P = 0.008). In PFA negative patients, MDR1 expression was higher when compared to PFA positive patients (P = 0.055). No such difference was found when analyzing peripheral blood samples. Our experiments showed no impact of MDR1 expression in bone marrow or peripheral blood cells on overall survival (P = 1.000 and P = 0.903 respectively). In summary, the present study shows the prognostic impact of MDR1 expression on induction of complete remission in AML patients. We confirmed that MDR1 overexpression is an unfavorable prognostic factor in AML, which may help to stratify the risk rate of PFA negative patients. In future studies, quantitative detection of MDR1 expression might be a valuable tool to predict prognosis in this patient subset.