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

Detection and management of acute myeloid leukemia measurable residual disease: is it standard of care?

PURPOSE OF REVIEW

In the present manuscript, we will review the current approaches to investigate measurable residual disease (MRD) and its clinical applications in AML management.

RECENT FINDINGS

Over the last decades, several methods have been developed to trace MRD, with flow cytometry and polymerase chain reaction (PCR) being the most reliable. However, new technologies, such as digital PCR and Next-Generation Sequencing are emerging as particularly useful in AML. The 2017 European LeukemiaNet (ELN) recommendations have incorporated MRD assessment to define the response criteria to therapy, and more recently, the ELN MRD Working Party has published guidelines for the use of MRD in clinical practice.

SUMMARY

Morphologic complete remission (mCR) after induction therapy, has been consistently shown not only to have a critical prognostic role but also to fail in predicting relapse on an individual basis. Major attempts to improve our prediction capability have been made by measuring the residual levels of leukemic cells that persist in the bone marrow after chemotherapy. This number of cells, also called MRD, harbors in the bone marrow below the threshold of morphology and is responsible for leukemia recurrence. Therefore, the detection of MRD promises to help predict the risk of relapse, allowing a more proper patients' risk-stratification and the use of risk-tailored therapeutic strategy.

New developments in diagnosis, prognostication, and treatment of advanced systemic mastocytosis

Systemic mastocytosis (SM) has greatly benefited from the broad application of precision medicine techniques to hematolymphoid neoplasms. Sensitive detection of the recurrent KIT D816V mutation and use of next-generation sequencing (NGS) panels to profile the genetic landscape of SM variants have been critical adjuncts to the diagnosis and subclassification of SM, and development of clinical-molecular prognostic scoring systems. Multilineage KIT involvement and multimutated clones are characteristic of advanced SM (advSM), especially SM with an associated hematologic neoplasm (AHN). A major challenge is how to integrate conventional markers of mast cell disease burden (percentage of bone marrow mast cell infiltration and serum tryptase levels) with molecular data (serial monitoring of both KIT D816V variant allele frequency and NGS panels) to lend more diagnostic and prognostic clarity to the heterogeneous clinical presentations and natural histories of advSM. The approval of the multikinase/KIT inhibitor midostaurin has validated the paradigm of KIT inhibition in advSM, and the efficacy and safety of second-generation agents, such as the switch-control inhibitor ripretinib (DCC-2618) and the D816V-selective inhibitor avapritinib (BLU-285) are being further defined in ongoing clinical trials. Looking forward, perhaps the most fruitful marriage of the advances in molecular genetics and treatment will be the design of adaptive basket trials that combine histopathology and genetic profiling to individualize treatment approaches for patients with diverse AHNs and relapsed/refractory SM.

Isavuconazole as Primary Antifungal Prophylaxis in Patients With Acute Myeloid Leukemia or Myelodysplastic Syndrome: An Open-label, Prospective, Phase 2 Study

BACKGROUND

Mold-active primary antifungal prophylaxis (PAP) is routinely recommended in neutropenic patients with newly diagnosed acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS) undergoing remission-induction chemotherapy (RIC). Isavuconazole (ISAV) is an extended spectrum mold-active triazole and has superior tolerability and fewer significant drug-drug interactions compared with other triazoles.

METHODS

In our investigator-initiated, phase 2 trial, treatment-naive adult patients with AML or MDS starting RIC received ISAV per the dosing recommendations in the US label until neutrophil recovery (absolute neutrophil count [ANC] ≥ 0.5 × 109/L) and attainment of complete remission, occurrence of invasive fungal infection (IFI), or for a maximum of 12 weeks. The primary endpoint was the incidence of proven/probable IFI during ISAV PAP and up to 30 days after the last dose.

RESULTS

Sixty-five of 75 enrolled patients received ISAV PAP (median age, 67 years, median ANC at enrollment, 0.72 × 109/L). Thirty-two patients (49%) received oral targeted leukemia treatments (venetoclax, FTL3 inhibitors). Including the 30-day follow-up period, probable/proven and possible IFIs were encountered in 4 (6%) and 8 patients (12%), respectively. ISAV trough serum concentrations were consistently > 1 µg/mL, showed low intraindividual variation, and were not significantly influenced by chemotherapy regimen. Tolerability of ISAV was excellent, with only 3 cases (5%) of mild to moderate elevations of liver function tests and no QTc prolongations.

CONCLUSIONS

ISAV is a safe and effective alternative for PAP in patients with newly diagnosed AML/MDS undergoing RIC in the era of recently approved or emerging small-molecule antileukemia therapies.

CLINICAL TRIALS REGISTRATION

NCT03019939.

A phase 1 study of azacitidine with high-dose cytarabine and mitoxantrone in high-risk acute myeloid leukemia

In this phase 1 study, azacitidine (AZA) was given before high-dose cytarabine (HiDAC) and mitoxantrone (mito) based on the hypothesis that epigenetic priming with a hypomethylating agent before cytotoxic chemotherapy would improve response rates in patients with high-risk acute myeloid leukemia (AML), including relapsed/refractory disease. The primary objective was to establish the recommended phase 2 dose of AZA given before standard HiDAC/mito. In a dose escalation scheme, 46 patients (median age, 66 years) received AZA at 37.5, 50, or 75 mg/m2 subcutaneously or IV once daily on days 1 to 5 followed by HiDAC (3000 mg/m2) and mitoxantrone (30 mg/m2) once each on days 6 and 10 (the HiDAC/mito dose was reduced 33% in elderly subjects). Two dose-limiting toxicities occurred (both in the same patient): acute liver failure and kidney injury at the 50 mg/m2 dose. The 30-day induction death rate was 2.2% (1 of 46). The overall response rate, including complete remission and complete remission with incomplete count recovery, was 61% (28 of 46). Previously untreated patients aged ≥60 years with therapy-related AML and de novo AML were more likely to respond than untreated patients with AML progressing from an antecedent hematologic disorder (myelodysplastic syndrome and chronic myelomonocytic leukemia). Patients with favorable European Leukemia Network risk (P = .008), NPM1 mutations (P = .007), or IDH2 mutations (P = .03) were more likely to respond, and those with TP53 mutations (P = .03) were less likely to respond. The recommended phase 2 dose of AZA is 75 mg/m2 per day on days 1 to 5 followed by HiDAC (3000 mg/m2) and mitoxantrone (30 mg/m2) once each on days 6 and 10. This trial was registered at www.clinicaltrials.gov as #NCT01839240.

Flow cytometric significance of cellular alkaline phosphatase activity in acute myeloid leukemia

In this prospective hospital-based cohort study that included 43 newly diagnosed patients with acute myeloid leukemia, flow cytometric cellular alkaline phosphatase (ALP) activity within primitive leukemic cells allowed us to identify two groups of patients at diagnosis according to the numbers of leukemic blasts expressing ≥ 12% of ALP+ cells (27 patients, Group A) and less than 12% of ALP+ cells (16 patients, Group B). Differences in outcome for complete response, relapse or treatment resistance, and exitus were statistically analyzed and were significant, when comparing the two groups. The overall survival (OS) and event-free survival (EFS) differences between Group A and B were statistically significant. The survival of Group A patients was significantly shorter than those for Group B. No significant relationship was detected in outcome when comparing ELN prognostic-risk group based on cytogenetic and molecular profile (patients in the favorable, intermediate, and adverse risk groups). Flow cytometric cellular ALP activity at diagnosis may be used to estimate relapses and disease persistence more accurately. The limitations of our study include the small number of patients enrolled and a short follow-up, due to its prospective nature.

Arsenic Trioxide and Thalidomide Combination Induces Autophagy Along with Apoptosis in Acute Myeloid Cell Lines

Objective

Autophagy and apoptosis play key roles in cancer survival and pathogenesis and are governed by specific genes which have a dual role in both cell death and survival. Arsenic trioxide (ATO) and thalidomide (THAL) are used for treatment of many types of hematologic malignancies. ATO prevents the proliferation of cells and induces apoptosis in some cancer cells. Moreover, THAL has immunomodulatory and antiangiogenic effects in malignant cells. The aim of present study was to examine the effects of ATO and THAL on U937 and KG-1 cells, and evaluation of mRNA expression level of VEGFs genes, PI3K genes and some of autophagy genes.

Materials and Methods

In this in vitro experimental study, U937 and KG-1 cells were treated by ATO (0.4-5 μM) and THAL (5-100 μM) for 24, 48 and 72 hours. Cell viability was measured by MTT assay. The apoptosis rate and cell cycle arrest were evaluated by flow cytometry (Annexin/PI) and cell cycle flow cytometry analysis, respectively. The effect of ATO/THAL on mRNAs expression was evaluated by real-time polymerase chain reaction (PCR).

Results

ATO/THAL combination enhanced cell apoptosis in a dose-dependent manner. Also, ATO/THAL induced SubG1/ G1 phase arrest. mRNA expression levels of VEGFC (contrary to other VEGFs isoform), PI3K, AKT, mTOR, MEK1, PTEN, IL6, LC3 and P62 genes were upregulated in acute myeloid leukemia (AML) cells following treatment with ATO/THAL.

Conclusion

Combined treatment with ATO and THAL can inhibit proliferation and invasion of AML cells by down-regulating ULK1 and BECLIN1 and up-regulating PTEN and IL6, and this effect was more marked than the effects of ATO and THAL alone.

[Clinical observation of 12 patients with refractory/relapsed acute myeloid leukemia treated with allogeneic hematopoietic stem cell transplantation containing cladribine regimen]

Objective: To investigate the safety and efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) containing cladribine sequential busulfan regimen for refractory/relapsed acute myeloid leukemia (AML) . Methods: The clinical data of 12 refractory/relapsed AML patients received allo-HSCT with cladribine sequential busulfan regimen. Results: ① Of the 12 patients, 9 were males and 3 females, with a median age of 36 (27-50) years. The donors were identical sibling (3) , matched unrelated (1) and haploidentical family member (9) respectively. Nine patients reached partial remission and other remained no remission after chemotherapy before allo-HSCT. The median previous chemotherapy courses before allo-HSCT were 6 (2-13) . ② Conditioning regimen: Smostine 250 mg·m(-2)·d(-1), d-7; Cladribine 5 mg·m(-2)·d(-1), d-6 to d-2; Cytarabine Arabinoside 2 g·m(-2)·d(-1), d-6 to d-2; Busulfan 3.2 mg·m(-2)·d(-1), d-6 to d-3; Rabbit anti-human thymocyte immunoglobulin (ATG) 1.5 mg·m(-2)·d(-1) (unrelated donor transplantation) or 2.0-2.5 mg·m(-2)·d(-1) (haplo-HSCT) , d-4 to d-1. ③ Of the 12 patients, 11 patients attained complete haploidentical engraftment, one case occurred primary graft failure. The median durations for neutrophils and platelet implantations were 15 (15-21) and 19 (17-30) days respectively. ④After conditioning, no hepatic veno-occlusive diseases were observed, hemorrhagic cystitis occurred in 2 patients, 8 patients had fever, 3 cases experienced acute GVHD grade II, localized chronic GVHD occurred in 8 patients. ⑤The median follow-up was 8 (4-12) months. Leukemia relapse occurred in 2 patients at time of 6, 12 months after allo-HSCT. The estimated 1-year OS and DFS were (71.1±1.8) % and (62.2±1.8) %, respectively. Conclusions: allo-HSCT with cladribine sequential busulfan regimen was a feasible choice with favorable outcome for refractory/relapsed AML.

Heterogeneity in refractory acute myeloid leukemia

Successful clinical remission to therapy for acute myeloid leukemia (AML) is required for long-term survival to be achieved. Despite trends in improved survival due to better supportive care, up to 40% of patients will have refractory disease, which has a poorly understood biology and carries a dismal prognosis. The development of effective treatment strategies has been hindered by a general lack of knowledge about mechanisms of chemotherapy resistance. Here, through transcriptomic analysis of 154 cases of treatment-naive AML, three chemorefractory patient groups with distinct expression profiles are identified. A classifier, four key refractory gene signatures (RG4), trained based on the expression profile of the highest risk refractory patients, validated in an independent cohort (n = 131), was prognostic for overall survival (OS) and refined an established 17-gene stemness score. Refractory subpopulations have differential expression in pathways involved in cell cycle, transcription, translation, metabolism, and/or stem cell properties. Ex vivo drug sensitivity to 122 small-molecule inhibitors revealed effective group-specific targeting of pathways among these three refractory groups. Gene expression profiling by RNA sequencing had a suboptimal ability to correctly predict those individuals resistant to conventional cytotoxic induction therapy, but could risk-stratify for OS and identify subjects most likely to have superior responses to a specific alternative therapy. Such personalized therapy may be studied prospectively in clinical trials.

Development and Validation of a Novel Acute Myeloid Leukemia-Composite Model to Estimate Risks of Mortality

Question

Can a model incorporating patient-specific (comorbidities and age) and acute myeloid leukemia (AML)-specific features (cytogenetic and molecular alterations) predict mortality after AML treatment?

Findings

In a multicenter cohort study of 1100 patients, we demonstrated that (1) comorbidities had a significant impact on 1-year mortality after initial therapy for AML, (2) an augmented hematopoietic cell transplant–comorbidity index (HCT-CI) was the best suited index for comorbidity evaluation in AML, and (3) an AML composite model of augmented HCT-CI, age, and cytogenetic/molecular risks has a strong AUC of 0.76 for 1-year mortality.

Meaning

An AML composite model can guide decision-making about treatment of AML.

Importance

To our knowledge, this multicenter analysis is the first to test and validate (1) the prognostic impact of comorbidities on 1-year mortality after initial therapy of acute myeloid leukemia (AML) and (2) a novel, risk-stratifying composite model incorporating comorbidities, age, and cytogenetic and molecular risks.

Objective

To accurately estimate risks of mortality by developing and validating a composite model that combines the most significant patient-specific and AML-specific features.

Design, Setting, and Participants

This is a retrospective cohort study. A series of comorbidities, including those already incorporated into the hematopoietic cell transplantation–comorbidity index (HCT-CI), were evaluated. Patients were randomly divided into a training set (n = 733) and a validation set (n = 367). In the training set, covariates associated with 1-year overall mortality at a significance level of P < .10 constructed a multivariate Cox proportional hazards model in which the impact of each covariate was adjusted for that of all others. Then, the adjusted hazard ratios were used as weights. Performances of models were compared using C statistics for continuous outcomes and area under the curve (AUC) for binary outcomes.

Exposures

Initial therapy for AML.

Main Outcomes and Measures

Death within 1 year after initial therapy for AML.

Results

A total of 1100 patients, ages 20 to 89 years, were treated for AML between January 1, 2008, and December 31, 2012, at 5 academic institutions specialized in treating AML; 605 (55%) were male, and 495 (45%) were female. In the validation set, the original HCT-CI had better C statistic and AUC estimates compared with the AML comorbidity index for prediction of 1-year mortality. Augmenting the original HCT-CI with 3 independently significant comorbidities, hypoalbuminemia, thrombocytopenia, and high lactate dehydrogenase level, yielded a better C statistic of 0.66 and AUC of 0.69 for 1-year mortality. A composite model comprising augmented HCT-CI, age, and cytogenetic/molecular risks had even better predictive estimates of 0.72 and 0.76, respectively.

Conclusions and Relevance

In this cohort study, comorbidities influenced 1-year survival of patients with AML, and comorbidities are best captured by an augmented HCT-CI. The augmented HCT-CI, age, and cytogenetic/molecular risks could be combined into an AML composite model that could guide treatment decision-making and trial design in AML. Studying physical, cognitive, and social health might further clarify the prognostic role of aging. Targeting comorbidities with interventions alongside specific AML therapy might improve survival.

Monocytes-neutrophils-ratio as predictive marker for failure of first induction therapy in AML

INTRODUCTION

Acute myeloid leukemia (AML) is, if untreated, a fatal hematologic neoplasia. Failure of the first induction chemotherapy is a hallmark for a poor prognosis. Early recognition of therapy failure is crucial for planning further therapies. Therefore, international guidelines recommend a bone marrow biopsy around day 14 after the beginning of induction therapy. Hypocellular bone marrow on day 14 is still gold standard for therapy assessment and further therapy strategy. Despite this, non-invasive ways for the evaluation of induction therapy were looked for in the past years.

METHODS

We collected peripheral blood cell counts and routine laboratory values of patients treated with "7 + 3" induction therapy. Ratios of absolute cell counts of monocytes and neutrophils (MNR) were calculated daily, and the values were compared in patients with failure of the first induction therapy and patients with therapy response.

RESULTS

54 patients were included, 12 of which had failure of first induction therapy. The MNR following therapy was highly correlated with the bone marrow results. With the right cut-off, the MNR provides a valid and reliable tool for identification of patients with failure of first induction therapy with a sensitivity of 83.3% and a specificity of 87.8% on day 18.

CONCLUSIONS

We propose a novel and non-invasive method for detection of failure of first induction therapy in patients with de novo AML and "7 + 3" induction therapy. The MNR is free of cost since the required cell counts are performed routinely for each patient undergoing intensive chemotherapy.

[Study of clinical outcome and prognosis in pediatric core binding factor-acute myeloid leukemia]

Objective: To analyze the clinical outcome and the prognostic factor in pediatric patients with core binding factor-acute myeloid leukemia (CBF-AML). Methods: A total of 121 newly diagnosed pediatric CBF-AML patients enrolled from Aug. 2005 to Sep. 2017 were retrospectively reviewed. Cumulative incidence of relapse (CIR), event-free survival (EFS) and overall survival (OS) rates were estimated by Kaplan-Meier method and prognostic factors were evaluated by Cox regression with SPSS. Results: Of the 121 patients, 120 patients were assessed for bone marrow remission after induction chemotherapy. 100 cases (83.3%) achieved complete remission (CR) after the first course of chemotherapy. 119 cases (99.2%) achieved CR after the second course of chemotherapy. Of the 121 patients, 13 patients (10.7%) had recurrence with the median interval of recurrence as 13.8 months (3.7 to 58.8 months). 17 patients (14.0%) died. The CIR, EFS and OS at 3 years were 12.7%, 77.5% and 82.8%, respectively. The factors including age at diagnosis, sex, initial WBC count, presence of extramedullary leukemia, C-KIT expression, additional chromosomal abnormalities, and CR after the first course of chemotherapy were analyzed by multivariate regression analysis of Cox. Multivariate analysis identified that additional chromosomal abnormalities was the only independent risk factor affecting OS (HR=4.289, 95%CI 1.070-17.183, P=0.040). Conclusions: Pediatric CBF-AML was a unique setting of prognostic subtypes. Chemotherapy produced good responses. Additional chromosomal abnormalities was the only independent risk factor for OS in pediatric CBF-AML.

Next Generation Sequencing in AML-On the Way to Becoming a New Standard for Treatment Initiation and/or Modulation?

Acute myeloid leukemia (AML) is a clonal disease caused by genetic abberations occurring predominantly in the elderly. Next generation sequencing (NGS) analysis has led to a deeper genetic understanding of the pathogenesis and the role of recently discovered genetic precursor lesions (clonal hematopoiesis of indeterminate/oncogenic potential (CHIP/CHOP)) in the evolution of AML. These advances are reflected by the inclusion of certain mutations in the updated World Health Organization (WHO) 2016 classification and current treatment guidelines by the European Leukemia Net (ELN) and National Comprehensive Cancer Network (NCCN) and results of mutational testing are already influencing the choice and timing of (targeted) treatment. Genetic profiling and stratification of patients into molecularly defined subgroups are expected to gain ever more weight in daily clinical practice. Our aim is to provide a concise summary of current evidence regarding the relevance of NGS for the diagnosis, risk stratification, treatment planning and response assessment in AML, including minimal residual disease (MRD) guided approaches. We also summarize recently approved drugs targeting genetically defined patient populations with risk adapted- and individualized treatment strategies.

[Therapeutic effect of combined use of interferon alpha-1b, interleukin-2 and thalidomide on reversing minimal residual disease in acute myeloid leukemia]

Objective: To explore the effect of combination regimen of interferon alpha-1b, interleukin-2 and thalidomide (ITI regimen) on minimal residual disease (MRD) in patients with acute myeloid leukemia (AML) who were in hematologic remission but MRD-positive. Methods: Eighteen patients (17 from Tumor Hospital of Zhengzhou University and 1 from the First People's Hospital of Pingdingshan City) with AML admitted from July 2016 to June 2018, who were in hematologic remission but MRD-positive were treated with different doses of ITI regimen, and the MRD levels were monitored. Results: Among 18 patients who received a conventional dose of ITI regimen for 1 to 2 months, 7 patients had undetectable MRD, 3 had significant decrease in MRD levels, 3 had elevated MRD level and had hematologic recurrence. Three patients with elevated MRD level received a higher dose of ITI regimen, 2 of them turned to MRD negative and the other 1 patient had decreased MRD level. The total response rate was 72.2%, and the response rate in patients with MRD > 1.0% was 57.1% (4/7) , and that of patients with MRD < 1.0% was 81.8% (9/11) , respectively. Conclusion: The ITI regimen can reduce the MRD level of patient with AML who are in hematologic remission but MRD-positive. The therapeutic effect could be improved by a higher dose administration of ITI regimen, and therapeutic effect may be negatively correlated with MRD level before treatment.

Stringent or nonstringent complete remission and prognosis in acute myeloid leukemia: a Danish population-based study

Stringent complete remission (sCR) of acute myeloid leukemia is defined as normal hematopoiesis after therapy. Less sCR, including non-sCR, was introduced as insufficient blood platelet, neutrophil, or erythrocyte recovery. These latter characteristics were defined retrospectively as postremission transfusion dependency and were suggested to be of prognostic value. In the present report, we evaluated the prognostic impact of achieving sCR and non-sCR in the Danish National Acute Leukaemia Registry, including 769 patients registered with classical CR (ie, <5% blasts in the postinduction bone marrow analysis). Individual patients were classified as having sCR (n = 360; 46.8%) or non-sCR (n = 409; 53.2%) based on data from our national laboratory and transfusion databases. Survival analysis revealed that patients achieving sCR had superior overall survival (hazard ratio [HR], 1.34; 95% confidence interval [CI], 1.10-1.64) as well as relapse-free survival (HR, 1.25; 95% CI, 1.03-1.51) compared with those with non-sCR after adjusting for covariates. Cox regression analysis regarding the impact of the stringent criteria for blood cell recovery identified these as significant and independent variables. In conclusion, this real-life register study supports the international criteria for response evaluation on prognosis and, most importantly, documents each of the 3 lineage recovery criteria as contributing independently.

Impact of Blood Count Recovery-based Complete Remission Before Allogeneic Hematopoietic Stem Cell Transplantation on Survival in Patients With Acute Myeloid Leukemia

BACKGROUND

Patients who achieve complete remission (CR) with incomplete blood count recovery (CRi) in acute myeloid leukemia (AML) have inferior overall survival and lower progression-free survival. The aim of this study was to define whether blood count recovery-based CR before allogeneic hematopoietic stem cell transplantation (alloHSCT) had an impact on survival in patients with AML.

MATERIALS AND METHODS

This study has been performed in a retrospective manner. One hundred one patients with AML who received an alloHSCT in our transplant center at Hacettepe University Hospital between the years 2001 and 2018 were evaluated. CRi were defined as bone marrow CR with absolute neutrophil count < 1000/mm³ and/or platelet count < 100.000/mm³. CR and CRi were confirmed just before alloHSCT in bone marrow and peripheral blood, respectively.

RESULTS

A total of 101 patients were entered into the study between 2001 and 2018. Median follow-up for all survivors was 38 months (range, 6-220 months). The 5-year overall survival for patients who were in CRi and patients who were in CR before transplantation were 58% and 67%, respectively (P = .68). The 5-year progression-free survival for patients who were in CRi and patients who were in CR before transplantation were 68% and 64%, respectively (P = .99).

CONCLUSION

In conclusion, we observed equivalent posttransplant outcomes between patients who were in CR and patients who were in CRi before alloHSCT. We assume that alloHSCT eliminated the negative effect of pre-transplant blood count levels.

Early recovery of the platelet count after decitabine-based induction chemotherapy is a prognostic marker of superior response in elderly patients with newly diagnosed acute myeloid leukaemia

BACKGROUND

Definite prognostic clinical factors of benefit for decitabine-based induction chemotherapy in elderly patients newly diagnosed with acute myeloid leukaemia (AML) are not identified. This study was designed to explore the potential biomarker, especially regeneration of haematopoiesis, of treatment response and survival in elderly patients with newly diagnosed AML.

METHOD

We analysed the clinical data of 117 elderly AML patients who were treated with a decitabine dose of 15 mg/m² for 5 days, granulocyte colony-stimulating factor of 300 μg/d for priming, plus cytarabine 10 mg/m² q12h for 7 days and aclarubicin 10 mg/d for 4 days (D-CAG).

RESULTS

After initial induction chemotherapy, the overall response rate and complete remission (CR) were 71.8% and 58.1%, respectively. Patients responding to the D-CAG regimen achieved higher platelet counts on day 14 after initial treatment (p < 0.001). Median counts were 59.5 × 10⁹/L in the CR group, 37 × 10⁹/L in the partial remission group and 28 × 10⁹/L in the non-responsive group. We then classified patients into those who achieved platelet counts≥60 × 10⁹/L or 100 × 10⁹/L on day 14 after D-CAG vs. those who did not. Platelet counts≥60 × 10⁹/L or 100 × 10⁹/L on day 14 were significantly associated with superior CR, overall survival and disease-free survival (80.9% vs. 45.3% p < 0.001,16.5 vs. 9.1 months p = 0.009 and 16.3 vs. 7.4 months p = 0.024; 85.2% vs. 50% p = 0.001, 31 vs. 10.1 months p = 0.003 and 16.9 vs. 8.9 months p = 0.006). Multivariate analysis confirmed that poor cytogenetics (p = 0.010) and FLT3-ITD mutation (p = 0.007) were identified as independent factors of OS, but not platelet count (p = 0.091). However, platelet count≥100 × 10⁹/L on day 14 was an independent prognostic factor of CR and DFS.

CONCLUSION

Platelet count recovery on day 14 after D-CAG induction chemotherapy is associated with response.

TRIAL REGISTRATION

D-CAG regimen was registered on ChicTR with number 11001700 .

Relative survival following response to 7 + 3 versus azacytidine is similar in acute myeloid leukemia and high-risk myelodysplastic syndromes: an analysis of four SWOG studies

Here we quantify and compare the absolute and relative overall survival (OS) benefits conveyed by complete remission (CR) in AML and high-risk MDS, and by CR with incomplete count recovery (CRi) in AML and by hematologic improvement (HI) in MDS, following treatment with 7+3 versus azacytidine.

We compared patients receiving 7+3 in SWOG studies S0106 (n=301) and S1203 (n=261) enrolling adults ≤ 60 years, with patients receiving azacytidine therapies in S0703 (n=133 AML patients ≥ 60) and S1117 (n=277 MDS patients ≥ 18). Absolute survival benefit was evaluated with 1-year, 3-year, and median OS; relative benefit was evaluated with univariate and covariate–adjusted hazard ratios.

CR conveyed a relative survival advantage in multivariable analysis, with a similar relative effect of CR across studies. CR also conferred an absolute survival benefit, but with a smaller magnitude of absolute benefit in the azacytidine trials. In AML, OS was similar for CRi and failure to achieve CR/CRi. In MDS, CR conferred a survival advantage versus HI, and HI did versus failure.

The relative survival benefit of CR was similar regardless of initial therapy for AML or high-risk MDS. With both therapies, CR has a beneficial effect on survival compared to CRi or HI.

Management of primary refractory acute myeloid leukemia in the era of targeted therapies

Primary refractory acute myeloid leukemia (AML), or primary induction failure, represents a continued challenge in clinical management. This review presents an overview of primary refractory disease and a discussion of risk factors for induction failure, including current evidence regarding the impact of karyotype and molecular mutation status on responsiveness to chemotherapy. We review the evidence for various treatment options for refractory AML including salvage chemotherapy regimens, allogeneic hematopoietic stem cell transplantation, targeted agents, and non-intensive therapies such as hypomethylating agents. A therapeutic approach to this patient population is presented, and several new and emerging therapies are reviewed.

Drug Shortage Impacts Patient Receipt of Induction Treatment

OBJECTIVE

Examine the impact of the 2011 shortage of the drug cytarabine on patient receipt and timeliness of induction treatment for Acute Myeloid Leukemia (AML).

STUDY DESIGN

A retrospective cohort was utilized to examine odds of receipt of inpatient induction chemotherapy and time to first dose across major (N = 105) and moderate (N = 316) shortage time periods as compared to a nonshortage baseline (N = 1,147).

DATA COLLECTION/EXTRACTION METHODS

De-identified patient data from 2008 to 2011 Surveillance, Epidemiology, and End Results (SEER) were linked to 2007-2013 Medicare claims and 2007-2013 Hospital Characteristics.

PRINCIPAL FINDINGS

Compared to prior nonshortage time period, patients diagnosed during a major drug shortage were 47 percent less likely (p < .05) to receive inpatient chemotherapy within 14 days of diagnosis. Patients who were younger, had a lower Charlson Comorbidity score, and for whom AML was a first primary cancer were prioritized across all periods.

CONCLUSIONS

Period of major shortage of a generic oncolytic, without an equivalent therapeutic substitute, reduced timely receipt of induction chemotherapy treatment. More favorable economic and regulatory policies for generic drug suppliers might result in greater availability of essential, older generic drug products that face prolonged or chronic shortage.

[The comparison of predicting clinical outcomes between immunolophenotype and hematological complete remission before human leukocyte antigen-matched sibling donor transplantation in acute myeloid leukemia]

Objective: To assess the prognostic significance of immunophenotype complete remission (ICR) and hematological complete remission (HCR) before human-leukocyte antigen (HLA)-matched sibling donor transplantation (MSDT) in acute myeloid leukemia (AML) patients. Methods: A cohort of 182 AML (non-APL) patients undergoing MSDT in HCR was retrospectively studied [including complete remission with ANC and PLT recovery (CR), CR with incomplete PLT recovery (CRp), CR with inconplete ANC and PLT recovery (CRi)]; ICR was determined as undetective minimal resudial disease (MRD) by multi-parameter flow cytometer. Results: ①Of the 182 patients, 97 were male, 85 female, and the median age was 41(4-62) years. ②The CR and CRi+CRp rates were 80.8% (147/182) and 19.2%(35/182), respectively; The 4-year cumulative incidence of relapse[CIR, (11.0±4.3)% vs (16.0±7.1)%, χ(2)=0.274, P=0.600], non-relapse mortality[NRM, (14.0±4.3)% vs (9.0±6.3)%, χ(2)=0.913, P=0.339], leukemia-free survival[LFS, (75.0±5.1)% vs (75.0±8.3)%, χ(2)=0.256, P=0.613], and overall survial [OS, (77.0±5.2)% vs (80.0±8.1)%, χ(2)=0.140, P=0.708] were comparable between the CRp+CRi and CR groups. ③Compared with the non-ICR group (n=35), the ICR group (n=147) showed lower 4-year CIR [(11.3±3.4) % vs (55.2±8.8) %, χ(2)=32.687, P<0.001], better 4-year LFS [(76.2±4.7)% vs (32.8±8.7)%, χ(2)=26.234, P<0.001] and OS[(79.0±4.7)% vs (39.0±9.1)%, χ(2)=25.253, P<0.001], and comparable NRM[(12.5±4.1)% vs (12.0±7.1)%, χ(2)=1.002, P=0.656]. ④Mulitvariate analysis confirmed the independent prognostic value of ICR in lower CIR [HR=11.026(95%CI 4.685-25.949), P<0.001], higher LFS [HR=5.785 (95% CI 2.974-11.254), P<0.001] and OS[HR=5.578 (95% CI 2.575-27.565), P<0.001]. Conclusion: The results indicated that ICR instead of HCR pre-transplantation had a significant prognostic value in AML patients undergoing MSDT.

The Prognostic Significance of Measurable ("Minimal") Residual Disease in Acute Myeloid Leukemia

PURPOSE OF REVIEW

The purpose of this review was to evaluate recent literature on detection methodologies for, and prognostic significance of, measurable ("minimal") residual disease (MRD) in acute myeloid leukemia (AML).

RECENT FINDINGS

There is no "one-fits-all" approach to MRD testing in AML. Most exploited to date are methods relying on immunophenotypic aberrancies (identified via multiparameter flow cytometry) or genetic abnormalities (identified via PCR-based assays). Current methods have important shortcomings, including the lack of assay platform standardization/harmonization across laboratories. In parallel to refinements of existing technologies and data analysis/interpretation, new methodologies (e.g., next-generation sequencing-based assays) are emerging that eventually may complement or replace existing ones. This dynamic evolution of MRD testing has complicated comparisons between individual studies. Nonetheless, an ever-growing body of data demonstrates that a positive MRD test at various time points throughout chemotherapy and hematopoietic cell transplantation identifies patients at particularly high risks of disease recurrence and short survival even after adjustment for other risk factors.

Measurement of Residual Disease in Acute Myeloid Leukemia

PURPOSE OF REVIEW

Assessment of measurable residual disease (MRD) after treatment can identify patients with acute myeloid leukemia (AML) that are at high risk of poor outcomes. However, there is no consensus yet regarding a standardized approach to measuring MRD that is most clinically meaningful. We review multiparameter flow cytometry (MFC) and reverse transcriptase polymerase chain reaction (RT-PCR), and discuss a framework for assessing remission MRD using next-generation sequencing (NGS).

RECENT FINDINGS

MFC and RT-PCR may not fully capitalize on the major advances that have been made in characterizing the genetic landscape of AML, which has offered insight into the biological and clinical implications of clonal genetic architecture. NGS has increasingly been shown to provide a qualitative and quantitative assessment of MRD with significant prognostic implications. The assessment of clonal architecture by NGS may complement or extend existing approaches for MRD monitoring. Long-term serial monitoring of diagnostic, remission, and relapse samples with clinical correlation will need to be performed in order to determine the impact of various MRD patterns using this technique.

Evaluating measurable residual disease in acute myeloid leukemia

Mounting evidence indicates that the presence of measurable ("minimal") residual disease (MRD), defined as posttherapy persistence of leukemic cells at levels below morphologic detection, is a strong, independent prognostic marker of increased risk of relapse and shorter survival in patients with acute myeloid leukemia (AML) and can be used to refine risk-stratification and treatment response assessment. Because of the association between MRD and relapse risk, it has been postulated that testing for MRD posttreatment may help guide postremission treatment strategies by identifying high-risk patients who might benefit from preemptive treatment. This strategy, which remains to be formally tested, may be particularly attractive with availability of agents that could be used to specifically eradicate MRD. This review examines current methods of MRD detection, challenges to adopting MRD testing in routine clinical practice, and recent recommendations for MRD testing in AML issued by the European LeukemiaNet MRD Working Party. Inclusion of MRD as an end point in future randomized clinical trials will provide the data needed to move toward standardizing MRD assays and may provide a more accurate assessment of therapeutic efficacy than current morphologic measures.

Evolving Treatment Strategies for Elderly Leukemia Patients with IDH Mutations

Acute myeloid leukemia (AML) is a debilitating and life-threatening condition, especially for elderly patients who account for over 50% of diagnoses. For over four decades, standard induction therapy with intensive cytotoxic chemotherapy for AML had remained unchanged. However, for most patients, standard therapy continues to have its shortcomings, especially for elderly patients who may not be able to tolerate the complications from intensive cytotoxic chemotherapy. New research into the development of targeted and alternative therapies has led to a new era in AML therapy. For the nearly 20% of diagnoses harboring a mutation in isocitrate dehydrogenase 1 or 2 (IDH1/2), potential treatment options have undergone a paradigm shift away from intensive cytotoxic chemotherapy and towards targeted therapy alone or in combination with lower intensity chemotherapy. The first FDA approved IDH2 inhibitor was enasidenib in 2017. In addition, IDH1 inhibitors are in ongoing clinical studies, and the oral BCL-2 inhibitor venetoclax shows preliminary efficacy in this subset of patients. These new tools aim to improve outcomes and change the treatment paradigm for elderly patients with IDH mutant AML. However, the challenge of how to best incorporate these agents into standard practice remains.

FDA Approval Summary: Mylotarg for Treatment of Patients with Relapsed or Refractory CD33-Positive Acute Myeloid Leukemia

On September 2, 2017, the U.S. Food and Drug Administration approved gemtuzumab ozogamicin (GO; Mylotarg; Pfizer, New York City, NY) for treatment of relapsed or refractory (R/R) CD33-positive acute myeloid leukemia (AML) in patients 2 years of age and older. GO is a CD33-directed antibody drug conjugate linked to the cytotoxic antibiotic calicheamicin. It originally received accelerated approval for treatment of older patients with relapsed CD33-positive AML in 2000, but it was withdrawn from the market in 2010 when the confirmatory trial failed to demonstrate clinical benefit among safety concerns, such as a higher rate of induction fatalities on the GO combination arm compared with chemotherapy alone. In addition, GO was associated with hepatic veno-occlusive disease (VOD), which has substantial morbidity and mortality. Pharmacokinetic analyses suggested a lower maximum concentration of GO would result in less VOD without affecting target saturation or efficacy. A meta-analysis across dose schedules of GO in patients with R/R AML showed that a lower-dose "fractionated" schedule of 3 mg/m² days 1, 4, and 7 was associated with less early mortality, hemorrhage, and VOD, without an apparent decrease in complete remission (CR) rate. MyloFrance 1 was a single-arm study evaluating response rates in patients with relapsed CD33-positive AML treated with the lower-dose fractionated GO regimen. The CR rate was 26% (95% confidence interval 16%-40%). Common adverse reactions were fever, infections, nausea, vomiting, constipation, bleeding, increased liver enzymes, and mucositis. There were no cases of VOD. These results supported the approval of GO as monotherapy for R/R CD33-positive AML using the lower-dose fractionated regimen.

IMPLICATIONS FOR PRACTICE

Gemtuzumab ozogamicin (GO) 3 mg/m² days 1, 4, and 7 is an active regimen for induction of remission when used to treat patients with relapsed or refractory CD33-positive acute myeloid leukemia without curative intent. The risks of hepatic veno-occlusive disease and early mortality with this regimen appear to be lower than reported previously for GO 9 mg/m² days 1 and 15. The data were not sufficient to enable conclusions about the safety of GO in children younger than 2 years of age.

Time to repeal and replace response criteria for acute myeloid leukemia?

The International Working Group (IWG) response criteria for acute myeloid leukemia, published in 2003, have remained the standard by which the efficacy of new drugs is measured in clinical trials. Over the last decade, concepts related to treatment response have been challenged by several factors; for example, the dissociation between early clinical response and survival outcome in older patients, the recognition that epigenetic and newer differentiating-agent therapies may produce delayed responses and also hematologic improvement/transfusion independence without a morphologic response, and evidence that remissions without minimal (or measurable) residual disease (MRD) may result in outcomes superior to those of morphologic remissions with persistent MRD. The evolving role of MRD status as a potential surrogate for predicting long-term survival has enhanced the clinical need to standardize and incorporate emerging technologies that enable deeper responses beyond those recognized by the IWG, and to pre-emptively identify patients at risk of early relapse. The potential for therapeutic interventions to erase MRD and alter the natural history represents an important and open research question. Reviewed here are some of the implications and challenges associated with establishing and incorporating new treatment response criteria, initially into clinical research, and eventually into real-world practice.

Comparison of outcomes following transplantation with T-replete HLA-haploidentical donors using post-transplant cyclophosphamide to matched related and unrelated donors for patients with AML and MDS aged 60 years or older

Allografting from HLA-haploidentical donors (HID) is being increasingly utilized worldwide for patients lacking a conventional matched donor. However, its efficacy in older patients with AML and MDS is unclear. We analyzed 127 consecutive allografts for AML/MDS patients aged ≥ 60 years at our center to compare outcomes using HID to those of contemporaneous transplants using matched sibling (MRD) or matched unrelated (MUD) donors. Patient characteristics were similar except HID transplants were more likely in non-white patients and were more commonly performed with reduced intensity conditioning and a marrow graft. For MRD, MUD and HID transplants respectively, 2-year estimates of non-relapse mortality (17, 23, and 9%), relapse (32, 34, and 33%), overall survival (OS) (62, 55, and 67%) and disease-free survival (DFS) (51, 43, and 58%) were not significantly different. Maximum cumulative incidences of grade 2-4 acute GVHD were not different (27, 37, 39%), but incidences of NIH grade moderate to severe (39, 35, 15%, p = 0.028 MUD vs. HID, p = 0.026 MRD vs. HID) and severe chronic GVHD (9, 12, 0%, p = 0.030 MUD vs. HID, p = 0.009 MRD vs. HID) were significantly higher in MRD and MUD than in HID transplants. On multivariable analysis, donor type was not a significant determinant of OS, DFS, TRM, or relapse. However, male gender and high/very high Disease Risk Index (DRI) were associated with significantly higher rates of relapse (HR 1.94, p = 0.047 for male gender, HR 2.48, p = 0.004 for high/very high DRI) and lower OS (HR 1.94, p = 0.018 for male gender, HR 1.80, p = 0.025 for high/very high DRI). HIDs are an acceptable alternative to matched donors in older patients with AML and MDS.

FDA Approval: Gemtuzumab Ozogamicin for the Treatment of Adults with Newly Diagnosed CD33-Positive Acute Myeloid Leukemia

On September 1, 2017, the FDA granted approval for gemtuzumab ozogamicin (Mylotarg; Pfizer Inc.) in combination with daunorubicin and cytarabine and as a monotherapy for the treatment of adult patients with newly diagnosed CD33-positive acute myeloid leukemia (AML). Gemtuzumab ozogamicin is a CD33-targeted antibody-drug conjugate joined to calicheamicin. Approval of gemtuzumab ozogamicin combination treatment was based on a randomized trial of 271 patients with newly diagnosed AML treated with daunorubicin and cytarabine with or without 3 mg/m² fractionated gemtuzumab ozogamicin, which resulted in an event-free survival (EFS) of 13.6 months for gemtuzumab ozogamicin + daunorubicin and cytarabine and 8.8 months for daunorubicin and cytarabine alone [HR = 0.68 (95% confidence interval (CI), 0.51-0.91)]. Hemorrhage, prolonged thrombocytopenia, and veno-occlusive disease were serious toxicities that were more common in patients treated with gemtuzumab ozogamicin + daunorubicin and cytarabine. Approval of gemtuzumab ozogamicin monotherapy was based on a randomized trial of 237 patients with newly diagnosed AML treated without curative intent. Median overall survival (OS) was 4.9 months with gemtuzumab ozogamicin versus 3.6 months on best supportive care [HR = 0.69 (95% CI, 0.53-0.90)]. Adverse events were similar on both arms. Postapproval, several studies are required including evaluation of fractionated gemtuzumab ozogamicin pharmacokinetics, safety of combination gemtuzumab ozogamicin in the pediatric population, immunogenicity, and the effects of gemtuzumab ozogamicin on platelet function. Clin Cancer Res; 24(14); 3242-6. ©2018 AACR.

Prognostic Prediction Model for Second Allogeneic Stem-Cell Transplantation in Patients With Relapsed Acute Myeloid Leukemia: Single-Center Report

PURPOSE

To identify factors affecting survival outcomes and to develop a prognostic model for second allogeneic stem-cell transplantation (allo-SCT2) for relapsed acute myeloid leukemia (AML) after the first autologous or allogeneic stem-cell transplantation.

PATIENTS AND METHODS

Seventy-eight consecutive adult AML patients who received allo-SCT2 were analyzed in this retrospective study.

RESULTS

The 4-year overall survival (OS) rate was 28.7%. In multivariate analysis, poor cytogenetic risk at diagnosis, circulating blast ≥ 20% at relapse, duration from first transplantation to relapse < 9 months, and failure to achieve morphologic complete remission after allo-SCT2 were factors associated with poor OS. A prognostic model was developed with the following score system: intermediate and poor cytogenetic risk at diagnosis (0.5 and 1 point), peripheral blast ≥ 20% at relapse (1 point), duration from the first transplantation to relapse < 9 months (1 point), and failure to achieve morphologic complete remission after allo-SCT2 (1 point). The model identified 2 subgroups according to the 4-year OS rate: 51.3% in the low-risk group (score < 2) and 2.8% in the high-risk group (score ≥ 2) (P < .001).

CONCLUSION

This prognostic model might be useful to make an appropriate decision for allo-SCT2 in relapsed AML after the first autologous or allogeneic stem-cell transplantation.

Phase 2 trial of a multivalent WT1 peptide vaccine (galinpepimut-S) in acute myeloid leukemia

A National Cancer Institute consensus study on prioritization of cancer antigens ranked the Wilms tumor 1 (WT1) protein as the top immunotherapy target in cancer. We previously reported a pilot study of a multivalent WT1 peptide vaccine (galinpepimut-S) in acute myeloid leukemia (AML) patients. We have now conducted a phase 2 study investigating this vaccine in adults with AML in first complete remission (CR1). Patients received 6 vaccinations administered over 10 weeks with the potential to receive 6 additional monthly doses if they remained in CR1. Immune responses (IRs) were evaluated after the 6th and 12th vaccinations by CD4+ T-cell proliferation, CD8+ T-cell interferon-γ secretion (enzyme-linked immunospot), or the CD8-relevant WT1 peptide major histocompatibility complex tetramer assay (HLA-A*02 patients only). Twenty-two patients (7 males; median age, 64 years) were treated. Fourteen patients (64%) completed ≥6 vaccinations, and 9 (41%) received all 12 vaccine doses. Fifteen patients (68%) relapsed, and 10 (46%) died. The vaccine was well tolerated, with the most common toxicities being grade 1/2 injection site reactions (46%), fatigue (32%), and skin induration (32%). Median disease-free survival from CR1 was 16.9 months, whereas the overall survival from diagnosis has not yet been reached but is estimated to be ≥67.6 months. Nine of 14 tested patients (64%) had an IR in ≥1 assay (CD4 or CD8). These results indicated that the WT1 vaccine was well tolerated, stimulated a specific IR, and was associated with survival in excess of 5 years in this cohort of patients. This trial was registered at www.clinicaltrials.gov as #NCT01266083.

Image-based ex-vivo drug screening for patients with aggressive haematological malignancies: interim results from a single-arm, open-label, pilot study

Background

Patients with refractory or relapsed haematological malignancies have few treatment options and short survival times. Identification of effective therapies with genomic-based precision medicine is hampered by intratumour heterogeneity and incomplete understanding of the contribution of various mutations within specific cancer phenotypes. Ex-vivo drug-response profiling in patient biopsies might aid effective treatment identification; however, proof of its clinical utility is limited.

Methods

We investigated the feasibility and clinical impact of multiparametric, single-cell, drug-response profiling in patient biopsies by immunofluorescence, automated microscopy, and image analysis, an approach we call pharmacoscopy. First, the ability of pharmacoscopy to separate responders from non-responders was evaluated retrospectively for a cohort of 20 newly diagnosed and previously untreated patients with acute myeloid leukaemia. Next, 48 patients with aggressive haematological malignancies were prospectively evaluated for pharmacoscopy-guided treatment, of whom 17 could receive the treatment. The primary endpoint was progression-free survival in pharmacoscopy-treated patients, as compared with their own progression-free survival for the most recent regimen on which they had progressive disease. This trial is ongoing and registered with ClinicalTrials.gov, number NCT03096821.

Findings

Pharmacoscopy retrospectively predicted the clinical response of 20 acute myeloid leukaemia patients to initial therapy with 88·1% accuracy. In this interim analysis, 15 (88%) of 17 patients receiving pharmacoscopy-guided treatment had an overall response compared with four (24%) of 17 patients with their most recent regimen (odds ratio 24·38 [95% CI 3·99–125·4], p=0·0013). 12 (71%) of 17 patients had a progression-free survival ratio of 1·3 or higher, and median progression-free survival increased by four times, from 5·7 (95% CI 4·1–12·1) weeks to 22·6 (7·4–34·0) weeks (hazard ratio 3·14 [95% CI 1·37–7·22], p=0·0075).

Interpretation

Routine clinical integration of pharmacoscopy for treatment selection is technically feasible, and led to improved treatment of patients with aggressive refractory haematological malignancies in an initial patient cohort, warranting further investigation.

Funding

Austrian Academy of Sciences; European Research Council; Austrian Science Fund; Austrian Federal Ministry of Science, Research and Economy; National Foundation for Research, Technology and Development; Anniversary Fund of the Austrian National Bank; MPN Research Foundation; European Molecular Biology Organization; and Swiss National Science Foundation.

[Factors associated with early treatment response in adults with acute myeloid leukemia]

Objective: To explore the factors influencing early treatment responses in adult with de novo acute myeloid leukemia (AML) . Methods: Data of consecutive newly-diagnosed AML (non-acute promyelocytic leukemia) adults were analyzed retrospectively. To assess the impact of clinical characteristics at diagnosis and induction regimen on achieving morphologic leukemia-free state (MLFS) , blood counts and minimal residual leukemia (MRD, positive MRD defined as RQ-PCR WT1 mRNA ≥0.6% and/or any level of abnormal blast population detected by flow cytometry) at the time of achieving MLFS. Results: 739 patients were included in this study. 406 (54.9%) patients were male, with a median age of 42 years (range, 18-65 years) . In the 721 evaluable patients, MLFS was achieved in 477 (66.2%) patients after the first induction regimen and 592 (82.1%) within two cycles. A total of 634 patients (87.9%) achieved MLFS, including 534 (84.2%) achieving a complete remission (CR, defined as MLFS with ANC ≥ 1×10(9)/L and PLT ≥ 100×10(9)/L) , 100 (15.8%) achieving a CRi (defined as MLFS with incomplete ANC or PLT recovery) , respectively. 260 (45.9%) patients of 566 (89.3%) who detected MRD at the time of achieving MLFS had positive MRD. Multivariate analyses showed that female gender, favorable-risk of SWOG criteria, IA10 and HAA/HAD as induction regimen were factors associated with achieving early MLFS. In addition, low bone marrow blasts, HGB ≥ 80 g/L, PLT counts<30×10(9)/L and mutated NPM1 without FLT3-ITD were factors associated with achieving MLFS after the first induction regimen; Negative FLT3-ITD mutation was factor associated with achieving MLFS within two cycles. PLT counts ≥30×10(9)/L and IA10, IA8 or HAA/HAD as induction chemotherapy were factors associated with achieving CR. Female gender, favorable-risk of SWOG criteria, FLT3-ITD mutation negative, mutated NPM1 without FLT3-ITD were factors associated with negative MRD. Conclusions: Female gender, favorable molecular markers or cytogenetics, and standard-dose induction regimen were key factors associated with higher probability of early and deep responses in adults with AML.

Acute Myeloid Leukemia: How Do We Measure Success?

The development and approval of novel, effective therapies for acute myeloid leukemia (AML) has lagged behind other malignancies. Judging success of therapy with meaningful endpoints is critical to development of new treatments. Overall survival (OS) has typically been the parameter necessary for regulatory approval of experimental therapy in AML. Herein, we discuss different strategies to define outcomes for patients with AML and their relative challenges.

Can Minimal Residual Disease Determination in Acute Myeloid Leukemia Be Used in Clinical Practice?

In acute myeloid leukemia (AML) that is in complete remission, minimal residual disease (MRD) is presumed to be present, though not morphologically evident. Advances in diagnostics now permit the detection and quantification of MRD in AML by several techniques. The level of MRD after induction and consolidation therapy correlates with disease sensitivity to chemotherapy and has greater power to predict long-term survival than patient and disease characteristics that are available at diagnosis, including genetic information. A unique advantage of MRD is that it is an integrated measure of the impact and interaction of genetics, epigenetics, host immune milieu, bone marrow environment, and drug sensitivity on disease response to treatment. Here, we review the main techniques for MRD assessment in AML, including polymerase chain reaction, multiparameter flow cytometry, and next-generation sequencing, with a focus on method-specific and general limitations to the optimal employment of MRD techniques for the determination of AML prognosis. We also review the data that establish the prognostic and predictive value of MRD assessment in AML. Finally, we provide recommendations for the use of MRD in the care of patients with AML in clinical practice today, including whether it should influence treatment decisions.

[Prognostic significance of blood count at the time of achieving morphologic leukemia-free state in adults with acute myeloid leukemia]

Objective: To explore prognostic significance of blood count at the time of achieving first morphologic leukemia-free state[complete remission (CR, ANC ≥1×10(9)/L and PLT ≥100×10(9)/L) , CR with incomplete PLT recovery (CRp) and CR with incomplete ANC and PLT recovery (CRi) ]in adult patients with de novo acute myeloid leukemia (AML) . Methods: From January 2008 to February 2016, data of consecutive newly-diagnosed AML (non-APL) adults who received continuous chemotherapy in our hospital were analyzed retrospectively. Results: 352 patients were included in the study. 179 (50.9%) were male. Median age was 44 (17-65) years. Using the SWOG cytogenetic classification, 87 (24.7%) , 171 (48.6%) , 46 (13.1%) and 48 (13.6%) patients belonged to favorable, intermediate, unfavorable and unknown categories, respectively. 16 (4.5%) had monosomal karyotype and 41 (11.6%) had FLT3-ITD mutation positive. Best response achieved at the time of achieving first morphologic leukemia-free state was CR in 299 (84.9%) patients, CRp in 26 (7.4%) and CRi in 27 (8.1%) . With a median follow-up period of 16 (2-94) months in survivors, the probabilities of cumulative incident of relapse (CIR) rate, disease free survival (DFS) and overall survival (OS) at 30 months were 47.5%, 46.0% and 58.6%, respectively. Multivariate analyses showed that non-CR (CRp or CRi) , was associated with high relapse rate, shorter DFS and OS. In addition, intermediate or high risk of SWOG cytogenetic classification and FLT3-ITD positive were common unfavorable factors affecting CIR, DFS and OS. Peripheral blast ≥60% at diagnosis was adverse factors affecting DFS. Age ≥48 years and bone marrow blasts ≥67% were associated with shorter OS. Conclusion: Blood count at the time of achieving morphologic leukemia-free state was one of the key markers associated with treatment outcomes in adults with AML.

Southwestern Oncology Group pretreatment risk criteria as predictive or prognostic factors in acute myeloid leukemia

Acute myeloid leukemia (AML) is a clonal hematological malignant condition and the implications of pretreatment risk criteria as predictive or prognostic factors are constantly under evaluation. With this study, the authors' intent was to characterize AML patients and to evaluate the clinical outcome associated with Southwestern Oncology Group (SWOG) coding pretreatment risk criteria/cytogenetic score. Between 2002 and 2010, 225 patients were diagnosed with AML at the Portuguese Institute of Oncology (Porto, Portugal). From this patient group, 128 patients aged <65 years were selected. The patients were treated using a combination of cytarabine and anthracycline, with the addition of cyclosporine when bone marrow dysplasia was observed. A median survival of 24 months was observed in this group. The patients were divided in subgroups according to the SWOG pretreatment risk criteria. We observed a statistically significant association of non-favorable SWOG coding with female gender [P=0.025; risk ratio (RR)=3.632, 95% confidence interval (CI): 1.113-11.852], indication for allogeneic bone marrow transplantation (P=0.023, RR=1.317, 95% CI: 1.184-1.465), complete response achievement (P=0.013, RR=1.385, 95% CI: 11.232-1.556) and relapse (P=0.048, RR=3.181, 95% CI: 10.966-10.478). Furthermore, SWOG pretreatment risk criteria also significantly affected global overall survival (OS; P=0.003) and OS at 5 years (P=0.001). A multivariate Cox regression analysis supported response to induction therapy (3-year OS: P=0.011, RR=0.385, 95% CI: 10.184-0.806; 5-year OS: P=0.012, RR=0.388, 95% CI: 10.597-1.994), consolidation (3-year OS: P=0.005, RR=0.328, 95% CI: 0.150-0.720; 5-year OS: P=0.002, RR=0.308, 95% CI: 0.144-0.657) and the diagnosis of therapy-related aml (3-year OS: P=0.016, RR=2.756, 95% CI: 0.486-1.281; 5-year OS: P=0.031, RR=2.369, 95% CI: 1.081-5.189) as prognostic factors, but this was not confirmed for SWOG pretreatment risk criteria. Therefore, we concluded that the reproducibility of the application of the SWOG pretreatment risk criteria may not be available as a prognostic factor in every acute leukemia population. However, its application as a predictive factor of response has been confirmed in our population.

Targeting the PI3K/AKT pathway via GLI1 inhibition enhanced the drug sensitivity of acute myeloid leukemia cells

Combination targeted therapy is commonly used to treat acute myeloid leukemia (AML) patients, particularly in refractory/relapse (RR) population. However, concerns have been raised regarding the safety and patient tolerance of combination chemotherapy. It is critical to choose the appropriate treatment for precision therapy. We performed genome-wide RNA profiling using RNA-Seq to compare the RR group and the complete remission (CR) group (a total of 42 adult AML patients). The Hedgehog (Hh) and PI3K/AKT pathways were upregulated in the RR population, which was further confirmed by western blot and/or qPCR. Overexpression of GLI1 in AML cells led to increased AKT phosphorylation and decreased drug sensitivity, which was attenuated by GLI1 inhibition. By contrast, neither the expression of GLI1 nor apoptosis in response to Ara-C treatment of AML cells was significantly affected by PI3K inhibition. Furthermore, co-inhibition of GLI1 and PI3K induced apoptosis of hematopoietic stem/progenitor cells (HSPCs), which raised serious concerns about the side effects of this treatment. These results indicated that GLI1 inhibition alone, but not combined inhibition, is sufficient to enhance AML drug sensitivity, which provides a novel therapeutic strategy for AML treatment.

Prognostic Significance of Residual Acute Myeloid Leukemia in Bone Marrow Samples Taken Prior to Allogeneic Hematopoietic Cell Transplantation

OBJECTIVES

We sought to identify features in routine evaluation of pre-hematopoietic cell transplantation (HCT) bone marrow samples from patients with acute myeloid leukemia (AML) that influenced patient outcome.

METHODS

Of 140 patients, evidence of residual leukemia (RL) was identified in 38 (27%) of pre-HCT samples, as defined by 5% or more aspirate blasts, increased blood blasts, clustered or necrotic blasts on biopsy specimens, and/or leukemia-associated karyotypic abnormalities.

RESULTS

Morphologic or karyotypic evidence of RL was significantly associated with shorter leukemia-free survival (LFS) compared with cases without identifiable RL (median, 7.1 vs 28.3 months; P  < .0001). Upon multivariable analysis, RL, prior relapse, age, high-risk karyotype, and alternate donor source were each independently associated with shorter LFS. RL in pre-HCT samples was more strongly associated with shorter LFS in patients with intermediate or favorable-risk AML karyotype ( P  = .001) than secondary or adverse karyotype-risk AML ( P  = .04).

CONCLUSIONS

Rigorous morphologic and karyotypic evaluation of pretransplant marrows is practical and important for posttransplant prognosis.