Effect of complete remission and responses less than complete remission on survival in acute myeloid leukemia: a combined Eastern Cooperative Oncology Group, Southwest Oncology Group, and M. D. Anderson Cancer Center Study

Unfavorable-risk acute myeloid leukemia dissected

PURPOSE OF REVIEW

Acute myeloid leukemia (AML) is an immensely heterogeneous disease based on the presence of varying combinations of morphologic, immunophenotypic, genetic, and molecular characteristics identified among those diagnosed with this disease. Although current therapeutic strategies provide a reasonable likelihood of achieving a complete remission for the majority of patients, relapse rates and subsequent disease-related mortality remain unacceptably high. Improved methods of risk stratification are needed to better identify patients at considerable risk of relapse in hopes of allowing for early therapeutic intervention and/or intensification that may lead to a higher likelihood of cure. The current status of risk stratification of AML and emerging technologies with potential to improve prognostic classification and outcomes are summarized in this review.

RECENT FINDINGS

Refinement of our understanding of the impact of current pretreatment AML cytogenetic, immunophenotypic, and molecular aberrations to predict outcomes and guide therapeutic decision-making is ongoing. Emerging data suggest that incorporation of the degree of posttreatment response and/or the detection of minimal residual disease can improve the accuracy of risk stratification for individual patients.

SUMMARY

Although pretreatment disease characteristics remain the hallmark of prognostication for AML patients, posttreatment parameters such as minimal residual disease assessment and degree of response to therapy possess the ability to further refine our identification of patients with unfavorable disease and thereby influence decisions regarding therapeutic planning.

Persistence of minimal residual disease assessed by multiparameter flow cytometry is highly prognostic in younger patients with acute myeloid leukemia

BACKGROUND

Predicting outcomes for patients with acute myeloid leukemia (AML) on the basis of pretreatment predictors has been the cornerstone of management. Posttreatment prognostic factors are increasingly being evaluated.

METHODS

Among 280 younger patients who were treated with intermediate-dose cytarabine (total ≥ 5 g/m² ) and idarubicin-based induction chemotherapy and achieved remission, 186 were assessed for minimal residual disease (MRD) with an 8-color multiparameter flow cytometry panel performed on bone marrow specimens with a sensitivity of 0.1% or higher.

RESULTS

One hundred sixty-six patients had samples available 1 to 2 months after induction at the time of complete remission (CR), and 79% became negative for MRD, with an MRD-negative status associated with an improvement in relapse-free survival (RFS; P = .0002) and overall survival (OS; P = .0002). One hundred sixteen were evaluated for their MRD status during consolidation, and 86% were negative, with an MRD-negative status associated with a significant improvement in RFS (P < .0001) and OS (P < .0001). Sixty-nine patients were evaluated for their MRD status after completion of all therapy, and 84% were negative, with an MRD-negative status associated with an improvement in RFS (P < .0001) and OS (P < .0001). In a multivariate analysis including age, cytogenetics, response (CR vs CR with incomplete platelet recovery/incomplete blood count recovery), and MRD, achieving an MRD-negative status was the most important independent predictor of RFS and OS at response (P = .008 and P = .0008, respectively), during consolidation (P < .0001 for both), and at the completion of therapy (P < .0001 and P = .002, respectively).

CONCLUSIONS

Achieving an MRD-negative status according to multiparameter flow cytometry is associated with a highly significant improvement in the outcomes of younger patients with AML receiving cytosine arabinoside plus idarubicin-based induction and consolidation regimens. Cancer 2017;123:426-435. © 2016 American Cancer Society.

Patients with Acute Myeloid Leukemia Admitted to Intensive Care Units: Outcome Analysis and Risk Prediction

Background

This retrospective, multicenter study aimed to reveal risk predictors for mortality in the intensive care unit (ICU) as well as survival after ICU discharge in patients with acute myeloid leukemia (AML) requiring treatment in the ICU.

Methods and Results

Multivariate analysis of data for 187 adults with AML treated in the ICU in one institution revealed the following as independent prognostic factors for death in the ICU: arterial oxygen partial pressure below 72 mmHg, active AML and systemic inflammatory response syndrome upon ICU admission, and need for hemodialysis and mechanical ventilation in the ICU. Based on these variables, we developed an ICU mortality score and validated the score in an independent cohort of 264 patients treated in the ICU in three additional tertiary hospitals. Compared with the Simplified Acute Physiology Score (SAPS) II, the Logistic Organ Dysfunction (LOD) score, and the Sequential Organ Failure Assessment (SOFA) score, our score yielded a better prediction of ICU mortality in the receiver operator characteristics (ROC) analysis (AUC = 0.913 vs. AUC = 0.710 [SAPS II], AUC = 0.708 [LOD], and 0.770 [SOFA] in the training cohort; AUC = 0.841 for the developed score vs. AUC = 0.730 [SAPSII], AUC = 0.773 [LOD], and 0.783 [SOFA] in the validation cohort). Factors predicting decreased survival after ICU discharge were as follows: relapse or refractory disease, previous allogeneic stem cell transplantation, time between hospital admission and ICU admission, time spent in ICU, impaired diuresis, Glasgow Coma Scale <8 and hematocrit of ≥25% at ICU admission. Based on these factors, an ICU survival score was created and used for risk stratification into three risk groups. This stratification discriminated distinct survival rates after ICU discharge.

Conclusions

Our data emphasize that although individual risks differ widely depending on the patient and disease status, a substantial portion of critically ill patients with AML benefit from intensive care.

Acute myeloid leukemia: 2016 Update on risk-stratification and management

Evidence suggest that even patients aged 70 or above benefit from specific AML therapy. The fundamental decision in AML then becomes whether to recommend standard or investigational treatment. This decision must rest on the likely outcome of standard treatment. Hence we review factors that predict treatment related mortality and resistance to therapy, the latter the principal cause of failure even in patients aged 70 or above. We emphasize the limitations of prediction of resistance based only on pre- treatment factors and stress the need to incorporate post-treatment factors, for example indicators of minimal residual disease. We review various newer therapeutic options and considerations that underlie the decision to recommend allogeneic hematopoietic cell transplant. Am. J. Hematol. 91:825-846, 2016. © 2016 Wiley Periodicals, Inc.

Tetraspanin CD82 Regulates the Spatiotemporal Dynamics of PKCα in Acute Myeloid Leukemia

Patients with acute myeloid leukemia (AML) have increased myeloid cells within their bone marrow that exhibit aberrant signaling. Therefore, therapeutic targets that modulate disrupted signaling cascades are of significant interest. In this study, we demonstrate that the tetraspanin membrane scaffold, CD82, regulates protein kinase c alpha (PKCα)-mediated signaling critical for AML progression. Utilizing a palmitoylation mutant form of CD82 with disrupted membrane organization, we find that the CD82 scaffold controls PKCα expression and activation. Combining single molecule and ensemble imaging measurements, we determine that CD82 stabilizes PKCα activation at the membrane and regulates the size of PKCα membrane clusters. Further evaluation of downstream effector signaling identified robust and sustained activation of ERK1/2 upon CD82 overexpression that results in enhanced AML colony formation. Together, these data propose a mechanism where CD82 membrane organization regulates sustained PKCα signaling that results in an aggressive leukemia phenotype. These observations suggest that the CD82 scaffold may be a potential therapeutic target for attenuating aberrant signal transduction in AML.

The outcome and prognostic factors of 248 elderly patients with acute myeloid leukemia treated with standard-dose or low-intensity induction therapy

The prognosis of elderly patients with acute myeloid leukemia (AML) is poor, and the recommendation of standard-dose or low-intensity induction regimen for these patients remains controversial. We retrospectively analyzed treatment outcome and prognostic factors of elderly AML patients who had received either standard-dose or low-intensity induction regimens.Two hundred forty-eight elderly AML patients with good Eastern Cooperative Oncology Group performance status (ECOG PS ≤ 2) received one of three regimens for induction in this study: standard-dose cytarabine plus idarubicin (IA; n = 144) or daunorubicin (DA; n = 42); low-intensity cytarabine, aclarubicin, and granulocyte colony-stimulating factor (G-CSF) (CAG; n = 62).After first induction treatment cycle, the overall complete remission (CR) rate was 42.7%. Patients in IA group had a higher CR rate than in DA or CAG group (49.3%, 35.7%, and 32.3%, respectively; P = 0.046). The 1-year, 3-year, and 5-year overall survival (OS) rates were 42.2%, 18.9%, and 13.5% for these 248 patients, with median survival of 9.2 months. Long-term survival of IA group was better than DA or CAG group. The 1-year, 3-year, and 5-year OS rates of IA group were 45.9%, 23.5%, and 19.4%, respectively, as compared to 39.8%, 8.3%, and estimated 2.4% in DA group, and 34.9%, 15.9%, and 6.3% in CAG group, respectively. Early induction mortality and 2-year relapse rates showed no difference among 3 groups. Univariate analysis and multivariate analysis identified lactic dehydrogenase (LDH) more than two times of upper normal limit at diagnosis and nonremission after first induction cycle as adverse prognostic factors for OS. A simple and valid scoring model was constructed for risk stratification and prediction of long-term survival of elderly AML patients.Standard-dose IA regimen could improve the prognosis of elderly AML patients with good performance status compared with standard-dose DA or low-intensity CAG regimen. All prognostic factors and risk assessment should be considered to ensure that each patient receives the suitable individualized treatment.

'Acute myeloid leukemia: a comprehensive review and 2016 update'

Acute myeloid leukemia (AML) is the most common acute leukemia in adults, with an incidence of over 20 000 cases per year in the United States alone. Large chromosomal translocations as well as mutations in the genes involved in hematopoietic proliferation and differentiation result in the accumulation of poorly differentiated myeloid cells. AML is a highly heterogeneous disease; although cases can be stratified into favorable, intermediate and adverse-risk groups based on their cytogenetic profile, prognosis within these categories varies widely. The identification of recurrent genetic mutations, such as FLT3-ITD, NMP1 and CEBPA, has helped refine individual prognosis and guide management. Despite advances in supportive care, the backbone of therapy remains a combination of cytarabine- and anthracycline-based regimens with allogeneic stem cell transplantation for eligible candidates. Elderly patients are often unable to tolerate such regimens, and carry a particularly poor prognosis. Here, we review the major recent advances in the treatment of AML.

[Efficacy and safety analysis of the combination of cladribine, cytarabine, granulocyte colonystimulating factor (CLAG) regime in patients with refractory or relapsed acute myeloid leukemia]

OBJECTIVE

To analyze efficacy and safety of CLAG regimen in patients with refractory or relapsed acute myeloid leukemia (AML).

METHODS

Efficacy and adverse events of patients with refractory or relapsed AML who were treated with one course of CLAG from April 1st, 2014 through December 9th, 2015 in our hospital were retrospectively reviewed.

RESULTS

Thirty- three patients (16 males and 17 females) with refractory or relapsed AML were treated with one course of CLAG with a median age of 49 (14-68) years. According to FAB subtype, there were 22 patients with M2, and 11 with other types. According to NCCN criteria, there were 6, 18 and 9 patients with favorable, intermediate and unfavorable risk respectively, including 5 with FLT3- ITD mutation. Of 16 refractory and 17 relapsed patients; the median previous chemotherapy courses were 2(1-36). After one course of CLAG, 78.8% (26/33) patients achieved hematological complete response (CR), with 93.8 %(15/16) in relapsed and 64.7 %(11/17) in refractory groups respectively. All five patients with FLT3- ITD mutation achieved CR. All patients had grade 4 neutropenia and thrombocytopenia and infection in different sites; three patients died early from infections. Five patients received allogeneic hematopoietic stem cell transplantation (allo- HSCT). Ten patients relapsed and thirteen patients died after the median follow-up 142(9-525) days. The median EFS and OS were 230 (9- 525) and 419(9- 525) days respectively, which in CR group (n=26) were significantly longer than those in NR one (n=7) [447 (165- 525) d vs 52 (9- 162) d,P <0.001].

CONCLUSIONS

CLAG regimen was effective and well tolerable in patients with refractory or relapsed AML, with the CR rate in relapsed patients higher than in refractory counterparts. Control of infections was imperative for treatment.

Hyper-recovery of platelets after induction therapy is a predictor of relapse-free survival in acute myeloid leukemia

We verified the association between standard clinical and laboratory variables and the risk of relapse in acute myeloid leukemia (AML), which led us to retrospectively examine the effect of regeneration of hematopoiesis in patients with newly diagnosed AML. We used data from 230 patients who obtained remission after cytarabine-based induction chemotherapy. Platelet counts ≥500 × 10⁹/L and hemoglobin levels ≥9 g/dL on day 28 after treatment initiation were significantly associated with relapse-free survival (RFS) rate, conferring respective multivariate risk ratios of 0.38 (95% CI: 0.18-0.79) and 0.60 (95% CI: 0.40-0.89) for the occurrence of relapse or death. No disease relapse occurred in core binding factor leukemia patients whose platelet counts recovered ≥500 × 10⁹/L at 28 days after therapy initiation. We conclude that regeneration of hematopoiesis, especially platelet hyper-recovery, after induction chemotherapy is a significant predictor of RFS in patients with AML.

The Time to Clearance of Peripheral Blood Blasts Predicts Complete Remission and Survival in Chinese Adults with Acute Myeloid Leukemia

The value of clearance of peripheral blood blasts (PBB) as a predictor of outcomes in acute myeloid leukemia (AML) is controversial. To investigate the prognostic significance of the time to clearance of PBB after induction in Chinese patients with AML, a retrospective analysis of 146 patients with newly diagnosed AML at Shanghai Ruijin Hospital was performed. Patients were categorized into early blast clearance (EBC; ≤5 days) and delayed blast clearance (DBC; >5 days) groups based on a receiver operating characteristic analysis. Complete remission (CR) after induction chemotherapy was related to the time to clearance of PBB (p < 0.001). Relapse-free survival (RFS; p = 0.003) and overall survival (p < 0.001) were longer in the EBC group. Multivariate analysis demonstrated that the time to clearance of PBB and cytogenetic risk independently predicted CR and RFS. Early clearance of PBB after induction chemotherapy can be a significant predictor of survival outcomes in AML patients.

Acute myeloid leukaemia

Acute myeloid leukaemia (AML) is a disorder characterized by a clonal proliferation derived from primitive haematopoietic stem cells or progenitor cells. Abnormal differentiation of myeloid cells results in a high level of immature malignant cells and fewer differentiated red blood cells, platelets and white blood cells. The disease occurs at all ages, but predominantly occurs in older people (>60 years of age). AML typically presents with a rapid onset of symptoms that are attributable to bone marrow failure and may be fatal within weeks or months when left untreated. The genomic landscape of AML has been determined and genetic instability is infrequent with a relatively small number of driver mutations. Mutations in genes involved in epigenetic regulation are common and are early events in leukaemogenesis. The subclassification of AML has been dependent on the morphology and cytogenetics of blood and bone marrow cells, but specific mutational analysis is now being incorporated. Improvements in treatment in younger patients over the past 35 years has largely been due to dose escalation and better supportive care. Allogeneic haematopoietic stem cell transplantation may be used to consolidate remission in those patients who are deemed to be at high risk of relapse. A plethora of new agents - including those targeted at specific biochemical pathways and immunotherapeutic approaches - are now in trial based on improved understanding of disease pathophysiology. These advances provide good grounds for optimism, although mortality remains high especially in older patients.

Should acute myeloid leukemia patients with actionable targets be offered investigational treatment after failing one cycle of standard induction therapy?

PURPOSE OF REVIEW

Therapeutic failure in acute myeloid leukemia remains common. It may be advantageous to identify patients with suboptimal treatment responses early as they may benefit from timely care strategy changes. Here, responses portending failure of standard induction therapy are reviewed and therapeutic options examined, including use of investigational, targeted agents for suitable patients.

RECENT FINDINGS

Patients entering complete remission without minimal residual disease early, that is, with one cycle of standard induction chemotherapy, have a lower relapse risk and live longer than other similarly-treated patients, supporting the proposition of early complete remission without minimal residual disease as a criterion for induction therapy success. Investigational small molecule drugs are appealing for patients who fail standard therapies, but complete remission rates as a single agent are typically modest.

SUMMARY

The relative value of different treatment strategies if a first standard induction therapy cycle fails to produce complete remission is unknown. However, retreatment with the same therapy often leads to complete remission and provides a benchmark against which other approaches should be compared. Addition of investigational small molecule drugs to standard reinduction therapy in patients with actionable targets could offer an attractive therapeutic strategy in this situation that might improve outcomes and facilitate clinical drug testing.

Allogeneic Hematopoietic Cell Transplantation for Acute Myeloid Leukemia: Time to Move Toward a Minimal Residual Disease-Based Definition of Complete Remission?

PURPOSE

Patients with acute myeloid leukemia (AML) who are in morphologic complete remission are typically considered separately from patients with active disease (ie, ≥ 5% marrow blasts by morphology) in treatment algorithms for allogeneic hematopoietic cell transplantation (HCT), which implies distinct outcomes for these two groups. It is well recognized that the presence of minimal residual disease (MRD) at the time of transplantation is associated with adverse post-HCT outcome for those patients in morphologic remission. This effect of pre-HCT MRD prompted us to compare outcomes in consecutive patients in MRD-positive remission with patients with active AML who underwent myeloablative allogeneic HCT at our institution.

PATIENTS AND METHODS

We retrospectively studied 359 consecutive adults with AML who underwent myeloablative allogeneic HCT from a peripheral blood or bone marrow donor between 2006 and 2014. Pre-HCT disease staging included 10-color multiparametric flow cytometry on bone marrow aspirates in all patients. Any level of residual disease was considered to be MRD positive.

RESULTS

Three-year relapse estimates were 67% in 76 patients in MRD-positive morphologic remission and 65% in 48 patients with active AML compared with 22% in 235 patients in MRD-negative remission. Three-year overall survival estimates were 26%, 23%, and 73% in these three groups, respectively. After multivariable adjustment, MRD-negative remission status remained statistically significantly associated with longer overall and progression-free survival as well as lower risk of relapse compared with MRD-positive morphologic remission status or having active disease, with similar outcomes between the latter two groups.

CONCLUSION

The similarities in outcomes between patients in MRD-positive morphologic remission and those with active disease at the time of HCT support the use of treatment algorithms that use MRD- rather than morphology-based disease assessments.

Should minimal residual disease guide therapy in AML?

The prognostic power of minimal residual disease after therapy for acute leukemias is not in question. It is only logical that the finding of leukemic blast cells after therapy predicts for impending relapse or at least the need for additional treatment. Which level of what is called minimal residual disease (MRD) is clinically relevant, however, depends on the efficacy of the initial treatment as well as the treatment strategies available to target MRD. There are a multitude of additional factors that can alter the clinical significance of MRD, including the genotype of the patient's leukemic cells. The fact that methodologies of MRD detection are not standardized and thresholds for defining MRD positivity vary depending upon MRD detection method and the operator's skills or convictions only add to the complexity of MRD interpretation. While enormous efforts are devoted to enhancing the sensitivity of MRD detection, eg, by next-generation sequencing, improvements of methods for detecting MRD per se will not automatically lead to a more reliable estimation of total tumor burden. Most importantly, even the best assay will yield accurate MRD results only if the tissue source for MRD determination is of good quality. Another aspect of potentially crucial importance is the heterogenous distribution of leukemic cells throughout the skeleton after treatment, recently demonstrated for acute myeloid leukemia (AML) by bone marrow imaging. Once technical difficulties of MRD measurement are resolved and better MRD-targeting drugs are developed, we still need to learn about alternate proposed mechanisms to explain MRD-independent prognostication, well described in acute lymphoid leukemia, before MRD can be included routinely in the guidance of therapy in AML.

Association Between Mutation Clearance After Induction Therapy and Outcomes in Acute Myeloid Leukemia

IMPORTANCE

Tests that predict outcomes for patients with acute myeloid leukemia (AML) are imprecise, especially for those with intermediate risk AML.

OBJECTIVES

To determine whether genomic approaches can provide novel prognostic information for adult patients with de novo AML.

DESIGN, SETTING, AND PARTICIPANTS

Whole-genome or exome sequencing was performed on samples obtained at disease presentation from 71 patients with AML (mean age, 50.8 years) treated with standard induction chemotherapy at a single site starting in March 2002, with follow-up through January 2015. In addition, deep digital sequencing was performed on paired diagnosis and remission samples from 50 patients (including 32 with intermediate-risk AML), approximately 30 days after successful induction therapy. Twenty-five of the 50 were from the cohort of 71 patients, and 25 were new, additional cases.

EXPOSURES

Whole-genome or exome sequencing and targeted deep sequencing. Risk of identification based on genetic data.

MAIN OUTCOMES AND MEASURES

Mutation patterns (including clearance of leukemia-associated variants after chemotherapy) and their association with event-free survival and overall survival.

RESULTS

Analysis of comprehensive genomic data from the 71 patients did not improve outcome assessment over current standard-of-care metrics. In an analysis of 50 patients with both presentation and documented remission samples, 24 (48%) had persistent leukemia-associated mutations in at least 5% of bone marrow cells at remission. The 24 with persistent mutations had significantly reduced event-free and overall survival vs the 26 who cleared all mutations. Patients with intermediate cytogenetic risk profiles had similar findings. [table: see text].

CONCLUSIONS AND RELEVANCE

The detection of persistent leukemia-associated mutations in at least 5% of bone marrow cells in day 30 remission samples was associated with a significantly increased risk of relapse, and reduced overall survival. These data suggest that this genomic approach may improve risk stratification for patients with AML.

Design and Validation of an Augmented Hematopoietic Cell Transplantation-Comorbidity Index Comprising Pretransplant Ferritin, Albumin, and Platelet Count for Prediction of Outcomes after Allogeneic Transplantation

Pretransplant values of serum ferritin, albumin, and peripheral blood counts were previously suggested to provide prognostic information about hematopoietic cell transplantation (HCT) outcomes. Whether these "biomarkers" have prognostic value independent of each other and the HCT-comorbidity index (HCT-CI) is unknown. We analyzed data from 3917 allogeneic HCT recipients at multiple sites in the United States and Italy using multivariate models including each biomarker and the HCT-CI. Data from all sites were then randomly divided into a training set (n = 2352) to develop weights for the relevant biomarkers to be added to the HCT-CI scores and a validation set (n = 1407) to validate an augmented HCT-CI compared with the original index. Multivariate analysis with data from one site showed that ferritin, albumin, and platelets-not neutrophils or hemoglobin-were independently associated with increased nonrelapse mortality (NRM) and decreased overall survival. Findings were validated in data from the other sites. Subsequently, in a training set from all sites, ferritin >2500 mg/dL (hazard ratio [HR], 1.69); albumin 3 to 3.5 g/dL (HR, 1.61) and <3.0 g/dL (HR, 2.27); and platelets 50 to <100,000 (HR, 1.28), 20 to <50,000 (HR, 1.29), and <20,000 (HR, 1.55) were statistically significantly associated with NRM. Weights were assigned to these laboratory values following the same equation used to design the original index. In the validation set, the addition of the biomarkers to the original index to develop an augmented HCT-CI resulted in a statistically significant increase in a higher c-statistic estimate for prediction of NRM (P = .0007). Ferritin, albumin, and platelet counts are important prognostic markers that further refine the discriminative power of the HCT-CI for transplant outcomes.

Multicentre survey to explore current survival of patients with acute myeloid leukaemia who failed induction chemotherapy

BACKGROUND

Acute myeloid leukaemia not responsive to first induction chemotherapy (PIF-AML) still remains a challenge, and there are only few recent epidemiological data regarding the outcome of these patients. In this multicentre survey, we evaluate the prognosis and outcome of patients with PIF-AML, who were diagnosed and treated in the last 5 yrs in four Italian institutions.

RESULTS

One hundred PIF-AML were recorded, 57 males and 43 females, with a median age of 63 yrs (19-79), 42% were younger than 60 yrs; 42% had a secondary AML and 40% had an adverse karyotype. According to cytogenetic/molecular risk stratification at diagnosis, 33% of patients were classified as favourable/intermediate-1 risk and 56% as intermediate-2/adverse risk. After a median follow-up of 11 months (1-49), 77% of patients died, while 23% were alive (with 12/23 in cCR). Thirty-six patients underwent allogeneic SCT, and of these, 11 of 36 (31%) were alive at last follow-up. The 12- and 24-month OS probability of the whole population was 45% and 21%, respectively. In multivariate analysis, the probability of OS of the whole population was significantly improved by Allo-SCT procedure (12-month OS probability 60% vs. 35%; P < 0.0001) and was better in patients with favourable/intermediate-1 risk at diagnosis (12-month OS probability 58% vs. 40%; P = 0.028). In transplanted cases, a pretransplant responsive disease was the only significant factor to predict a favourable outcome after Allo-SCT (P = 0.006).

CONCLUSION

Treatment options of PIF-AML still are limited and the prognosis, even recently, remains extremely poor. This survey shows that PIF-AML is still rarely cured without Allo-SCT and confirms the importance of initiating an urgent unrelated donor search in cases without a matched sibling donor. Moreover, the outcome of Allo-SCT is better in patients who achieve a good AML debulking before transplant. To reach this goal, new predictive scores and new protocols of salvage therapy (with target drugs or combinations) need to be explored urgently in PIF-AML.

Idarubicin, cytarabine, and pravastatin as induction therapy for untreated acute myeloid leukemia and high-risk myelodysplastic syndrome

Previous studies suggest that idarubicin/cytarabine(ara-C)/pravastatin (IAP) is an active salvage regimen for patients with AML. We therefore investigated this regimen in patients with newly-diagnosed AML or MDS (≥10% blasts). Patients were eligible if the anticipated treatment-related mortality (TRM) was <10%. Patients received pravastatin (1,280 mg/day po; days 1-8), cytarabine (1.5 g/m(2) /day; days 4-7), and idarubicin (12 mg/m(2) /day, days 4-6). Up to 3 cycles of consolidation with a shortened course was permitted. The primary endpoints were "good CR" rate (CR on day 35 without minimal residual disease) and TRM in the first 28 days. The study was to stop if after each cohort of 5 patients (a) the Bayesian posterior probability was < 5% that the true "good CR rate" was ≥ 70% or (b) the posterior probability was >25% that the TRM rate was ≥5%. Twenty-four patients were included. Conventional CR was achieved in 15 (63%) patients but only 12 (50%) achieved "good CR". 4 of 12 (33%) patients with "good CR" relapsed at median of 16 weeks (10.5-19). Five (21%) patients had refractory disease. Survival probability at 1 year was 72% (48.7-64). Two (8.3%) patients died within 28 days from multiorgan failure. The most common grade 3-4 adverse effects were febrile neutropenia (75%) and diarrhea (25%). Based on the stopping rules accrual ceased after entry of these 24 patients. IAP did not meet the predefined efficacy criteria for success. Therefore, we would not recommend this regimen for phase three testing in this patient subset.

Relation of Clinical Response and Minimal Residual Disease and Their Prognostic Impact on Outcome in Acute Myeloid Leukemia

Purpose

Both presence of minimal residual disease (MRD) and achievement of complete remission (CR) with incomplete platelet recovery (CRp) rather than CR after induction therapy predict relapse in acute myeloid leukemia (AML). These results suggest a correlation between response (peripheral count recovery) and MRD at the time of morphologic remission. Here we examine this hypothesis and whether MRD and response provide independent prognostic information after accounting for other relevant covariates.

Patients and Methods

We retrospectively analyzed data from 245 adults with AML who achieved CR, CRp, or CR with incomplete blood count recovery (CRi) after induction therapy. Bone marrow samples were collected on or closest to the first date of blood count recovery, and MRD was determined by 10-color multiparameter flow cytometry.

Results

The 71.0% of patients who achieved CR had MRD less frequently and had lower levels of MRD than the 19.6% of patients achieving CRp and 9.4% achieving CRi. Although pretreatment covariates such as cytogenetics, monosomal karyotype, relapsed or refractory rather than newly diagnosed AML, and FLT3 internal tandem duplication were associated with relapse, their prognostic effect was much lower once MRD and response were taken into account, the univariable statistical effect of which was not materially affected by inclusion of pretreatment covariates.

Conclusion

Our data indicate that post-therapy parameters including MRD status and response are important independent prognostic factors for outcome in patients with AML achieving remission. MRD status and type of response (CR v CRp or CRi) should play important, and perhaps dominant, roles in planning postinduction therapy.

Hematologic Recovery after Pretransplant Chemotherapy Does Not Influence Survival after Allogeneic Hematopoietic Cell Transplantation in Acute Myeloid Leukemia Patients

Pretransplant remission status in patients with acute myeloid leukemia (AML) is 1 of the most important factors determining their outcomes after allogeneic hematopoietic cell transplantation (allo-HCT). Most patients are in complete remission with full hematologic recovery (CR) before undergoing allo-HCT. However, some patients achieve CR without recovery of platelet count (CRp) or a morphologic leukemia-free state (MLFS), defined as meeting all CR criteria without recovery of both neutrophil and platelet counts. Currently, there is a paucity of data regarding transplant outcomes in AML patients achieving MLFS after chemotherapy. To address this question, we evaluated transplant outcomes in 270 AML patients who received 6/6 HLA-matched sibling or 10/10 HLA-matched unrelated donor transplantation at a single institution between 2006 and 2013. Of our 270 patients, 206 were in CR, 45 were in CRp, and 19 were in MLFS before allo-HCT. Patients in CR, CRp, or MLFS had similar 3-year overall survival rates (49%, 46%, and 47%, respectively; P = .88) and 3-year event-free survival rates (45%, 36%, and 40%, respectively; P = .53). However, the cumulative incidence of nonrelapse mortality was significantly higher in patients in MLFS compared with those in CR (58% versus 22%, P = .0004), whereas the cumulative incidence of relapse in patients in MLFS was significantly lower compared with those in CR (11% versus 36%, P = .03). Our results suggest that survival outcomes in AML patients are not influenced by degree of hematologic recovery before allo-HCT.

Mitigating Fear and Loathing in Managing Acute Myeloid Leukemia

The contemporary care of patients with acute myeloid leukemia (AML) is made complex by potentially toxic treatments, continuously advancing science, aging patients, and individual treatment goals. By taking a survey of present-day approaches, we aim to dispel some of the trepidation surrounding that care of patients with AML. At the beginning is the initial presentation, and we will discuss whether or not AML should be considered a medical emergency. We will explore the complex realm of patient decision-making about initial therapy, including the intricate straits of patient-doctor communication, and available options for initial treatment. We will then address post-remission approaches and the controversies that lie therein, and survivorship issues. Finally, we will investigate the current role molecular assessments are playing in therapy recommendations.

How I treat the older patient with acute myeloid leukemia

Acute myeloid leukemia (AML) in older patients presents a notable therapeutic challenge to the clinical hematologist. The clinical biology of AML among patients is highly heterogeneous. Interpatient variations are relevant for prognosis and treatment choice. Outcome of treatment for patients of advanced age is often compromised by comorbid conditions and an enhanced susceptibility to toxicities from therapy. Here we present selected clinical vignettes that highlight distinct representative situations derived from clinical practice. The vignettes are specifically discussed in light of the perspective of treating older patients with leukemia. We review the clinical significance of various cytogenetic and molecular features of the disease, and we examine the various currently available treatment options as well as the emerging prognostic algorithms that may offer guidance in regard to personalized therapy recommendations. The dilemmas in tailoring treatment selection in this category of patients with AML are the central theme in this discussion.

Allogeneic hematopoietic cell transplantation for acute myeloid leukemia in older adults

Acute myeloid leukemia (AML) is primarily a disease of the elderly and the numbers of these patients are increasing. Patients ≥60 years of age continue to have poor prognosis. Preliminary results suggest benefit from reduced-intensity allogeneic hematopoietic cell transplantation (HCT) in selected patients 60-80 years of age. However, although patients in this age range comprise >50% of those with AML, they currently constitute only 17% of those offered HCT. In the absence of prospective randomized studies comparing HCT and chemotherapy, the decision to recommend HCT rests on retrospective analyses of the risks of relapse and nonrelapse mortality after each approach. There is strong evidence that pre-HCT comorbidities can predict HCT-related morbidity and mortality. Age alone does not appear predictive and, particularly if the risk of relapse with chemotherapy is high, should not be the sole basis for deciding against HCT. Use of geriatric assessment tools, inflammatory biomarkers, and genetic polymorphism data may further aid in predicting nonrelapse mortality after HCT. Disease status and pretreatment cytogenetics with FLT3-TID, NPM-1, and CEBP-α status are the main factors predicting relapse and these are likely to be supplemented by incorporation of other molecular markers and the level of minimal residual disease after chemotherapy. HLA-matched related and unrelated donor grafts seem preferable to those from other donor sources. Donor age is of no clear significance. Models combining comorbidities with AML risk factors are useful in risk assessment before HCT. In this chapter, we integrated information on AML-specific, HCT-specific, and patient-specific risk factors into a risk-adapted approach to guide decisions about HCT versus no HCT.

Acute myeloid leukemia: 2014 update on risk-stratification and management

OVERVIEW

Evidence suggests that even patients aged 70 or above benefit from specific AML therapy. The fundamental decision in AML then becomes whether to recommend standard or investigational treatment. This decision must rest on the likely outcome of standard treatment. Hence we review factors that predict treatment related mortality and resistance to therapy, the latter the principal cause of failure even in patients aged 70 or above. We emphasize the limitations of prediction of resistance based only on pre-treatment factors and stress the need to incorporate post-treatment factors, for example indicators of minimal residual disease. We review various newer therapeutic options and considerations that underlie the decision to recommend allogeneic hematopoietic cell transplant.

Management of older or unfit patients with acute myeloid leukemia

Acute myeloid leukemia (AML) is primarily a disease of older adults, for whom optimal treatment strategies remain controversial. Because of the concern for therapeutic resistance and, in particular, excessive toxicity or even treatment-related mortality, many older or medically unfit patients do not receive AML-directed therapy. Yet, evidence suggests that outcomes are improved if essentially all of these patients are offered AML therapy, ideally at a specialized cancer center. Medical fitness for tolerating intensive chemotherapy can be estimated relatively accurately with multiparameter assessment tools; this information should serve as basis for the assignment to intensive or non-intensive therapy. Until our accuracy in predicting the success of individual therapies improves, all patients should be considered for participation in a randomized controlled trial. Comparisons between individual trials will be facilitated once standardized, improved response criteria are developed, and standard treatment approaches have been defined against which novel therapies can be tested.

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 7+3 treatment. The goal was to determine efficacy and identify patient subgroups that may benefit from CPX-351 treatment. Response rate (complete remission + 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 < .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 ≥1000: 36 vs 32; platelets >100 000: 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.

The protein phosphatase 2A regulatory subunit B55α is a modulator of signaling and microRNA expression in acute myeloid leukemia cells

We recently discovered that the protein phosphatase 2A (PP2A) B55α subunit (PPP2R2A) is under-expressed in primary blast cells and is unfavorable for remission duration in AML patients. In this study, reverse phase protein analysis (RPPA) of 230 proteins in 511 AML patient samples revealed a strong correlation of B55α with a number of proteins including MYC, PKC α, and SRC. B55α suppression in OCI-AML3 cells by shRNA demonstrated that the B subunit is a PKCα phosphatase. B55α does not target SRC, but rather the kinase suppresses protein expression of the B subunit. Finally, the correlation between B55α and MYC levels reflected a complex stoichiometric competition between B subunits. Loss of B55α in OCI-AML3 cells did not change global PP2A activity and the only isoform that is induced is the one containing B56α. In cells containing B55α shRNA, MYC was suppressed with concomitant induction of the competing B subunit B56α (PPP2R5A). A recent study determined that FTY-720, a drug whose action involves the activation of PP2A, resulted in the induction of B55α In AML cells, and a reduction of the B subunit rendered these cells resistant to FTY-720. Finally, reduction of the B subunit resulted in an increase in the expression of miR-191-5p and a suppression of miR-142-3p. B55α regulation of these miRs was intriguing as high levels of miR-191 portend poor survival in AML, and miR-142-3p is mutated in 2% of AML patient samples. In summary, the suppression of B55α activates signaling pathways that could support leukemia cell survival.

Predictive factors for latency period and a prognostic model for survival in patients with therapy-related acute myeloid leukemia

Therapy-related acute myeloid leukemia (t-AML) is an increasingly recognized sequela in patients receiving chemotherapy or radiotherapy for a primary malignancy or autoimmune disease. This study assessed factors related to the latency period (LP) between the antecedent disorder (AD) and t-AML diagnosis and developed a comprehensive prognostic model to predict overall survival (OS). We evaluated a cohort of newly diagnosed t-AML patients treated with cytarabine-based induction therapy from 2001 to 2011. Multivariable linear and proportional hazards models were used to assess the impact of different classes of chemotherapy on the LP and to identify independent prognostic factors for OS. Of 730 treated AML patients, 58 (7.9%) had t-AML. Median LP to t-AML was 5.6 years (range, 0.5-38.4). 64% of patients achieved CR and median OS was 10.7 months. Independent prognostic factors of short LP were age at AD (P < 0.0001) and prior treatment with mitotic inhibitors (P = 0.05). Unfavorable cytogenetics (P = 0.004), antecedent hematologic or autoimmune disease (P = 0.01), age >60 (P = 0.03), and platelet count <30,000 μL (P = 0.04) at the time of t-AML diagnosis were prognostic for inferior OS. A prognostic model using these factors was developed that risk stratified t-AML patients into two groups: favorable and unfavorable. Patients in the favorable group had a median OS of 37.6 months compared with 6.4 months in patients comprising the unfavorable group (P < 0.0001). Multicomponent prognostic models integrating disease or treatment-related covariates can help better understand how t-AML evolves; and can be clinically useful in risk stratifying t-AML patients undergoing induction therapy.

Phase I study of clofarabine in adult patients with acute myeloid leukemia in Japan

OBJECTIVE

There are limited treatment options for relapsed/refractory acute myeloid leukemia patients or previously untreated elderly (≥60 years) patients with acute myeloid leukemia. In Phase II studies from the USA and Europe, single-agent clofarabine demonstrated activity and acceptable toxicity in elderly patients with previously untreated acute myeloid leukemia. This Phase I, multicenter study assessed the maximum-tolerated dose, safety, pharmacokinetics and efficacy of clofarabine in Japanese adults with acute myeloid leukemia.

METHODS

Intravenous clofarabine (20, 30 and 40 mg/m(2)/day) was administered for 5 days to Japanese adult patients with relapsed or refractory acute myeloid leukemia or elderly patients with newly diagnosed acute myeloid leukemia.

RESULTS

Fourteen patients, median age of 67.5 (59-72) years, were enrolled in this study. Eleven out of 14 patients had relapsed/refractory acute myeloid leukemia. Three patients received clofarabine at 20 mg/m(2), six at 30 mg/m(2) and five at 40 mg/m(2). Frequently reported treatment-related adverse events included thrombocytopenia (100%), anemia (93%), neutropenia (86%), nausea (86%), alanine aminotransferase increase (71%), headache (71%) and febrile neutropenia (57%). Three patients experienced reversible dose-limiting toxicities; two had increased alanine aminotransferase with 30 and 40 mg/m(2) and one had Grade 3 elevation of serum amylase with 40 mg/m(2). The maximum-tolerated dose was 30 mg/m(2)/day. Cmax and exposure area under the curve0-24h increased with increasing dose and were proportional to dose through the tested dose range. Among the 14 assessable patients, four (29%) achieved complete remission and two (14%) complete remission without platelet recovery. The overall remission rate was 43%.

CONCLUSIONS

These results demonstrate safety and preliminary, promising activity of clofarabine in Japanese patients with acute myeloid leukemia. Further investigation is warranted.

Risk assessment before allogeneic hematopoietic cell transplantation for older adults with acute myeloid leukemia

Acute myeloid leukemia (AML) most commonly affects patients older than 60 years. Outcomes of treatment of older AML patients have been poor. The advent of reduced-intensity conditioning (RIC) regimens made allogeneic hematopoietic cell transplantation (HCT) an available treatment option with curative intent for older AML patients. Because older patients are often excluded from clinical trials, little is known about the stratification of their risks before allogeneic HCT. While recent studies of RIC and allogeneic HCT have shown little impact of age on outcomes, other variables such as the recipient health status and the AML disease status and chromosomal aberrations have proven to be of prognostic significance. Here, the authors review recent studies of allogeneic HCT for older patients with AML with detailed evaluation of risk factors for relapse as well as non-relapse mortality. The authors have integrated the currently available information on transplant risks into a five-category risk-benefit system that could aid in the decision-making in this patient population.

Gemtuzumab ozogamicin for treatment of newly diagnosed acute myeloid leukaemia: a systematic review and meta-analysis

Evidence regarding the efficacy of gemtuzumab ozogamicin (GO) addition to standard induction chemotherapy in newly diagnosed acute myeloid leukaemia (AML) is conflicting. This systematic review aimed to identify and summarize all evidence regarding the benefits and harms of adding GO to conventional chemotherapy for induction treatment of AML. A comprehensive literature search of two databases (PUBMED and Cochrane) from inception up to November 22, 2012, and 4 years of proceedings from four major haematology/oncology conferences was undertaken. Endpoints included benefits (complete remission, relapse-free, event-free, and overall survival), and harms (early mortality and incidence of hepatic veno-occlusive disease/sinusoidal obstructive syndrome). Seven trials (3942 patients) met all inclusion criteria. Addition of GO showed improved relapse-free [Hazard Ratio (HR) = 0·84 (95% confidence interval (CI) 0·71-0·99)] and event-free survival [HR = 0·59 (95%CI 0·48-0·74)] but not overall survival [HR = 0·95 (95%CI 0·83-1·08)]. Addition of GO resulted in higher rate of early mortality [Risk Ratio = 1·60 (95%CI 1·07-2·39)]. Improved overall survival was observed in studies using a lower cumulative GO dose (<6 mg/m(2) ) [HR = 0·89 (95%CI 0·81-0·99)]. Addition of GO to conventional chemotherapy as induction therapy may improve relapse-free and event-free survival, but does not impact overall survival and significantly increases early mortality in AML.

Genetic biomarkers in acute myeloid leukemia: will the promise of improving treatment outcomes be realized?

Recent progress in the molecular genetics of acute myeloid leukemia (AML) has shown this disease to be more heterogeneous than previously realized. Recurrent cytogenetic and mutational changes in leukemic blasts have been confirmed to have high prognostic significance. High-throughput techniques to analyze the AML genome in greater depth have revealed novel mutations with putative roles in leukemogenesis. The use of prognostic biomarkers has allowed for a more detailed categorization of AML based on risk. Despite this tremendous progress, the understanding of the mechanisms by which these changes influence leukemia growth and response to treatment is still limited, which in turn has hindered the development of rationally targeted therapies for AML. The integration of clinical, cytogenetic and molecular data will be essential to translate the current research momentum into better outcomes for patients with AML.

Acute myeloid leukaemia in adults

The outlook for patients with acute myeloid leukaemia has improved in the past 30 years. Unlike other cancers, much of this progress is attributable to refinement of supportive treatment, rather than the introduction of new drugs. New antibacterial and antifungal agents, antiemetics, and improved transfusion support have decreased the rate of early death, and morbidity and mortality from allogeneic stem cell transplantation has been substantially reduced. However, more than half of young adult patients and about 90% of older patients still die from their disease. Refractoriness to initial induction treatment and, more frequently, relapse after complete remission, are still the main obstacles to cure. Accordingly, new treatment approaches with mechanisms of action different from those of conventional chemotherapy are needed. Our knowledge of the various chromosomal and molecular abnormalities implicated in the pathogenesis of the many subtypes of the disease has greatly expanded; as a result, clinical research is moving towards the investigation of new non-cytotoxic agents in combination with chemotherapy. The goal is to target the molecular abnormalities identified at diagnosis; however, several aberrations can coexist in subclones of acute myeloid leukaemia, making the disease less likely to be inhibited by a single agent.

Acute myeloid leukemia: 2012 update on diagnosis, risk stratification, and management

DISEASE OVERVIEW

Acute myeloid leukemia (AML) results from accumulation of abnormal immature cells in the marrow. These cells interfere with normal hematopoiesis can escape into the blood and infiltrate lung and CNS. The most common cause of death is bone marrow failure. It is likely that many different mutations and/or epigenetic aberrations can produce the same disease, with these differences responsible for the very variable response to therapy, which is AML's principal clinical feature.

DIAGNOSIS

This rests on demonstration that the marrow or blood has >20% blasts of myeloid lineage. Blast lineage is assessed by multiparameter flow cytometry with CD33 and CD13 being surface markers typically expressed by myeloid blasts. It should be realized that clinical/prognostic considerations, not the blast % per se, should be the main factor determining how a patient is treated.

RISK STRATIFICATION

Two features determine risk: the probability of treatment-related mortality (TRM) and, more important, even in patients aged >75 with Zubrod performance status 1, the probability of resistance to standard therapy despite not incurring TRM. The chief predictor of resistance is cytogenetics with a monosomal karyotype (MK) denoting the disease is essentially incurable with standard therapy even if followed by a standard allogeneic transplant (HCT). The most common cytogenetic finding is a normal karyotype (NK) and those of such patients with an NPM1 mutation but no FLT3 internal tandem duplication (ITD), or with a CEBPA mutation, have a prognosis similar to that of patients with the most favorable cytogenetics [inv(16) or t(8;21)] (60-70% cure rate). In contrast, NK patients with a FLT3 ITD have only a 30-40% chance of cure even after HCT. Accordingly analyses of NPM1, FLT3, and CEBPA should be part of routine evaluation, much as is cytogenetics. Risk is best assessed considering several variables simultaneously rather than, for example, only age.

RISK-ADAPTED THERAPY

Patients with inv(16) or t(8;21) or who are NPM1+/FLT3ITD- can receive standard therapy (daunorubicin + cytarabine) and should not receive HCT in first CR. It seems likely that use of a daily daunorubicin dose of 90 mg/m(2) will further improve outcome in these patients. There appears no reason to use doses of cytarabine > 1 g/m(2) (for example, bid × 6 days), as opposed to the more commonly used 3 g/m(2) . Patients with an unfavorable karyotype (particularly MK) are unlikely to benefit from standard therapy (even with dose escalation) and are thus prime candidates for clinical trials of new drugs or new approaches to HCT; the latter should be done in first CR. Patients with intermediate prognoses (for example, NK and NPM and FLT3ITD negative) should also receive HCT in first CR and can plausibly receive either investigational or standard induction therapy, with the same prognostic information about standard therapy leading one patient to choose the standard and another an investigational option.