[What is recommended in the treatment of acute myeloid leukemia?] / Was ist gesichert in der Therapie der akuten myeloischen Leukämie?

Acute myeloid leukemia (AML) is characterized by a malignant transformation and proliferation of myeloid progenitor cells that cause a replacement of normal hematopoiesis. Diagnostic workup for AML includes cytogenetic analysis and mutational screening covering frequently mutated genes in AML. The genetic analysis is required for risk stratification and treatment decisions. Very recently, three novel drugs have been approved for patients who can be intensively treated: a tyrosine kinase inhibitor (midostaurin) for patients with FLT3 mutations, a liposomal formulation of chemotherapy (CPX) for patients with features of secondary AML, and a CD33 antibody-drug conjugate (gemtuzumab-ozogamicin) for AML with CD33 expression. Allogeneic stem cell transplantation remains an important treatment strategy for patients with intermediate- or high-risk AML and for patients with relapsed AML. For elderly patients who cannot undergo intensive treatment, demethylating agents are the treatment of choice. The aim is to prolong life expectancy with acceptable quality of life. In recent clinical trials, novel drugs have shown promising results in this patient population. Some of these drugs have already been approved in the US. Among these drugs are the Bcl­2 inhibitor venetoclax, which is already approved in Germany for chronic lymphatic leukemia, as well as IDH1/IDH2 inhibitors (the latter for patients with IDH1/IDH2 mutated AML). Acute promyelocytic leukemia represents a special type of AML that should be treated with a combination of all-trans retinoic acid and arsenic trioxide leading to excellent outcome.

Epidemiological, genetic, and clinical characterization by age of newly diagnosed acute myeloid leukemia based on an academic population-based registry study (AMLSG BiO).

We describe genetic and clinical characteristics of acute myeloid leukemia (AML) patients according to age from an academic population-based registry. Adult patients with newly diagnosed AML at 63 centers in Germany and Austria were followed within the AMLSG BiO registry (NCT01252485). Between January 1, 2012, and December 31, 2014, data of 3525 patients with AML (45% women) were collected. The median age was 65 years (range 18-94). The comparison of age-specific AML incidence rates with epidemiological cancer registries revealed excellent coverage in patients < 70 years old and good coverage up to the age of 80. The distribution according to the European LeukemiaNet (ELN) risk categorization from 2010 was 20% favorable, 31% intermediate-1, 28% intermediate-2, and 21% adverse. With increasing age, the relative but not the absolute prevalence of patients with ELN favorable and intermediate-1 risk (p < 0.001), with activating FLT3 mutations (p < 0.001), with ECOG performance status < 2 (p < 0.001), and with HCT-CI comorbidity index < 3 (p < 0.001) decreased. Regarding treatment, obesity and favorable risk were associated with an intensive treatment, whereas adverse risk, higher age, and comorbidity index > 0 were associated with non-intensive treatment or best supportive care. The AMLSG BiO registry provides reliable population-based distributions of genetic, clinical, and treatment characteristics according to age.

Consensus of German transplant centers on hematopoietic stem cell transplantation in Fanconi anemia.

Allogeneic hematopoietic stem cell transplantation (HSCT) is currently the only curative therapy for the severe hematopoietic complications associated with Fanconi anemia (FA). In Germany, it is estimated that 10-15 transplants are performed annually for FA. However, because FA is a DNA repair disorder, standard conditioning regimens confer a high risk of excessive regimen-related toxicities and mortality, and reduced intensity regimens are linked with graft failure in some FA patients. Moreover, development of graft-versus-host disease is a major contributing factor for secondary solid tumors. The relative rarity of the disorder limits HSCT experience at any single center. Consensus meetings were convened to develop a national approach for HSCT in FA. This manuscript outlines current experience and knowledge about HSCT in FA and, based on this analysis, general recommendations reached at these meetings.

[Myelodysplastic syndromes]. / Myelodysplastische Syndrome.

Myelodysplastic syndrome (MDS) encompasses a heterogeneous group of diseases originating in hematopoietic stem cells and is characterized by inefficient hematopoiesis and dysplastic changes in the bone marrow. In peripheral blood patients show anemia (mostly macrocytic), frequently accompanied by neutropenia and thrombocytopenia. Thus, clinically the patients suffer from fatigue (anemia), increased bleeding (thrombocytopenia) and infectious complications (neutropenia). Approximately one quarter of MDS patients develop acute myeloid leukemia (AML) in the course of the disease, which is characterized by a 20 % or more increase of blasts in the bone marrow. The estimated overall survival as well as the risk for AML transformation can be calculated with the international prognostic scoring system (IPSS) as well as the revised IPSS score (IPSS-R). Novel sequencing methods (e.g. next generation sequencing) allow the detection of recurrent gene mutations in MDS patients. Genes of the splicing machinery as well as genes involved in epigenetic regulation (e.g. ASXL1 and TET2) are most frequently mutated in MDS. Therapy is selected based on the patient risk profile (IPSS). Allogeneic stem cell transplantation is a curative approach for high risk patients (i.e. IPSS int-2 and higher) with a good performance status and a biological age below 70 years. Otherwise, high risk patients are treated with demethylating agents (e.g. decitabine and azacitidine). Low risk patients (IPSS low and int-1) mainly receive supportive therapy including iron chelation. An exceptional position is presented by MDS with an isolated 5q deletion as it can be treated with lenalidomide with good success. Enrolling patients in clinical trials is strongly recommended to improve the prospects of this disease.

Prognostic significance of FLT3 internal tandem duplication, nucleophosmin 1, and CEBPA gene mutations for acute myeloid leukemia patients with normal karyotype and younger than 60 years: a systematic review and meta-analysis.

Diagnosis and classification of acute myeloid leukemia (AML) are based on morphology and genetics. An increasing number of gene mutations have been found, and some are used for risk classification in AML patients with normal karyotype (cytogenetically normal (CN)-AML). In this systematic review and meta-analysis, we examined three frequent mutations in CN-AML: mutations of fms-related tyrosine kinase 3 (FLT3-ITD), mutated nucleophosmin (NPM1), and mutations of the CCAAT enhancer-binding protein alpha (CEBPA) gene. A systematic literature search of publications listed in the electronic databases (Embase, Pubmed, Healthstar, BIOSIS, ISI Web of Knowledge and Cochrane) from 2000 up to March 2012 was performed (Fig. 1). Nineteen studies were included and qualitatively analyzed. Two to four studies entered the quantitative meta-analysis incorporating 1,378 to 1,942 patients with CN-AML. Meta-analysis for overall survival (OS) and relapse-free survival (RFS) showed FLT3-ITD to predict an unfavorable prognosis, with hazard ratios (HR) of 1.86 and 1.75, respectively. In contrast, meta-analysis of the impact of NPM1 and CEBPA mutations on OS yielded an HR of 0.56 for each mutation, while analysis of impact on RFS produced HRs of 0.37 and 0.42, respectively. This systematic review and meta-analysis aimed to evaluate the prognostic value of mutations in the NPM1, CEBPA, and FLT3 genes. FLT3-ITD was associated with worse prognosis, whereas mutations in NPM1 and CEBPA genes were associated with a favorable prognosis.

Randomized phase-III study of low-dose cytarabine and etoposide + /- all-trans retinoic acid in older unfit patients with NPM1-mutated acute myeloid leukemia.

The aim of this randomized clinical trial was to evaluate the impact of all-trans retinoic acid (ATRA) in combination with non-intensive chemotherapy in older unfit patients (> 60 years) with newly diagnosed NPM1-mutated acute myeloid leukemia. Patients were randomized (1:1) to low-dose chemotherapy with or without open-label ATRA 45 mg/m2, days 8-28; the dose of ATRA was reduced to 45 mg/m2, days 8-10 and 15 mg/m2, days 11-28 after 75 patients due to toxicity. Up to 6 cycles of cytarabine 20 mg/day s.c., bid, days 1-7 and etoposide 100 mg/day, p.o. or i.v., days 1-3 with (ATRA) or without ATRA (CONTROL) were intended. The primary endpoint was overall survival (OS). Between May 2011 and September 2016, 144 patients (median age, 77 years; range, 64-92 years) were randomized (72, CONTROL; 72, ATRA). Baseline characteristics were balanced between the two study arms. The median number of treatment cycles was 2 in ATRA and 2.5 in CONTROL. OS was significantly shorter in the ATRA compared to the CONTROL arm (p = 0.023; median OS: 5 months versus 9.2 months, 2-years OS rate: 7% versus 10%, respectively). Rates of CR/CRi were not different between treatment arms; infections were more common in ATRA beyond treatment cycle one. The addition of ATRA to low-dose cytarabine plus etoposide in an older, unfit patient population was not beneficial, but rather led to an inferior outcome.The clinical trial is registered at clinicaltrialsregister.eu (EudraCT Number: 2010-023409-37, first posted 14/12/2010).

Randomized phase-II trial evaluating induction therapy with idarubicin and etoposide plus sequential or concurrent azacitidine and maintenance therapy with azacitidine.

The aim of this randomized phase-II study was to evaluate the effect of substituting cytarabine by azacitidine in intensive induction therapy of patients with acute myeloid leukemia (AML). Patients were randomized to four induction schedules for two cycles: STANDARD (idarubicin, cytarabine, etoposide); and azacitidine given prior (PRIOR), concurrently (CONCURRENT), or after (AFTER) therapy with idarubicin and etoposide. Consolidation therapy consisted of allogeneic hematopoietic-cell transplantation or three courses of high-dose cytarabine followed by 2-year maintenance therapy with azacitidine in the azacitidine-arms. AML with CBFB-MYH11, RUNX1-RUNX1T1, mutated NPM1, and FLT3-ITD were excluded and accrued to genotype-specific trials. The primary end point was response to induction therapy. The statistical design was based on an optimal two-stage design applied for each arm separately. During the first stage, 104 patients (median age 62.6, range 18-82 years) were randomized; the study arms PRIOR and CONCURRENT were terminated early due to inefficacy. After randomization of 268 patients, all azacitidine-containing arms showed inferior response rates compared to STANDARD. Event-free and overall survival were significantly inferior in the azacitidine-containing arms compared to the standard arm (p < 0.001 and p = 0.03, respectively). The data from this trial do not support the substitution of cytarabine by azacitidine in intensive induction therapy.

DNMT3A mutant transcript levels persist in remission and do not predict outcome in patients with acute myeloid leukemia.

We investigated the prognostic impact of minimal residual disease (MRD) monitoring in acute myeloid leukemia patients harboring DNA methyltransferase 3A-R882H/-R882C mutations (DNMT3Amut). MRD was determined by real-time quantitative PCR (RQ-PCR) in 1494 samples of 181 DNMT3Amut patients. At the time of diagnosis, DNMT3Amut transcript levels did not correlate with presenting clinical characteristics and concurrent gene mutations as well as the survival end points. In Cox regression analyses, bone marrow (BM) DNMT3Amut transcript levels (log10-transformed continuous variable) were not associated with the rate of relapse or death. DNMT3Amut transcript levels were significantly higher in BM than in blood after induction I (P=0.01), induction II (P=0.05), consolidation I (P=0.004) and consolidation II (P=0.008). With regard to the clinically relevant MRD time points, after two cycles of induction and at the end of therapy, DNMT3Amut transcript levels had no impact on the end point remission duration and overall survival. Of note, only a minority of the patients achieved RQ-PCR negativity, whereas most had constantly high DNMT3Amut transcript levels, a finding which is consistent with the persistence of clonal hematopoiesis in hematological remission.

Impact of salvage regimens on response and overall survival in acute myeloid leukemia with induction failure.

We evaluated the impact of salvage regimens and allogeneic hematopoietic cell transplantation (allo-HCT) in acute myeloid leukemia (AML) with induction failure. Between 1993 and 2009, 3324 patients with newly diagnosed AML were enrolled in 5 prospective treatment trials of the German-Austrian AML Study Group. After first induction therapy with idarubicin, cytarabine and etoposide (ICE), 845 patients had refractory disease. In addition, 180 patients, although responding to first induction, relapsed after second induction therapy. Of the 1025 patients with induction failure, 875 (median age 55 years) received intensive salvage therapy: 7+3-based (n=59), high-dose cytarabine combined with mitoxantrone (HAM; n=150), with all-trans retinoic acid (A; A-HAM) (n=247), with gemtuzumab ozogamicin and A (GO; GO-A-HAM) (n=140), other intensive regimens (n=165), experimental treatment (n=27) and direct allo-HCT (n=87). In patients receiving intensive salvage chemotherapy (n=761), response (complete remission/complete remission with incomplete hematological recovery (CR/CRi)) was associated with GO-A-HAM treatment (odds ratio (OR), 1.93; P=0.002), high-risk cytogenetics (OR, 0.62; P=0.006) and age (OR for a 10-year difference, 0.75; P<0.0001). Better survival probabilities were seen in an extended Cox regression model with time-dependent covariables in patients responding to salvage therapy (P<0.0001) and having the possibility to perform an allo-HCT (P<0.0001). FLT3 internal tandem duplication, mutated IDH1 and adverse cytogenetics were unfavorable factors for survival.

Acute myeloid leukemia derived from lympho-myeloid clonal hematopoiesis.

We studied acute myeloid leukemia (AML) patients with lympho-myeloid clonal hematopoiesis (LM-CH), defined by the presence of DNA methyltransferase 3A (DNMT3A) mutations in both the myeloid and lymphoid T-cell compartment. Diagnostic, complete remission (CR) and relapse samples were sequenced for 34 leukemia-related genes in 171 DNMT3A mutated adult AML patients. AML with LM-CH was found in 40 patients (23%) and was associated with clonal hematopoiesis of indeterminate potential years before AML, older age, secondary AML and more frequent MDS-type co-mutations (TET2, RUNX1 and EZH2). In 82% of AML patients with LM-CH, the preleukemic clone was refractory to chemotherapy and was the founding clone for relapse. Both LM-CH and non-LM-CH MRD-positive AML patients who achieved CR had a high risk of relapse after 10 years (75% and 75%, respectively) compared with patients without clonal hematopoiesis in CR with negative MRD (27% relapse rate). Long-term survival of patients with LM-CH was only seen after allogeneic hematopoietic stem cell transplantation (HSCT). We define AML patients with LM-CH as a distinct high-risk group of AML patients that can be identified at diagnosis through mutation analysis in T cells and should be considered for HSCT.

Pan-mutant-IDH1 inhibitor BAY1436032 is highly effective against human IDH1 mutant acute myeloid leukemia in vivo.

Neomorphic mutations in isocitrate dehydrogenase 1 (IDH1) are frequently found in several human cancer types including acute myeloid leukemia (AML) and lead to the production of high levels of the oncometabolite (R)-2-hydroxyglutarate (R-2HG). Here we report the characterization of BAY1436032, a novel pan-mutant IDH1 inhibitor, both in vitro and in vivo. BAY1436032 specifically inhibits R-2HG production and colony growth, and induces myeloid differentiation of AML cells carrying IDH1R132H, IDH1R132C, IDH1R132G, IDH1R132L and IDH1R132S mutations. In addition, the compound impacts on DNA methylation and attenuates histone hypermethylation. Oral administration of BAY1436032 led to leukemic blast clearance, myeloid differentiation, depletion of leukemic stem cells and prolonged survival in two independent patient-derived xenograft IDH1 mutant AML mouse models. Together, BAY1436032 is highly effective against all major types of IDH1 mutant AML.

Enantiomer-specific and paracrine leukemogenicity of mutant IDH metabolite 2-hydroxyglutarate.

Canonical mutations in IDH1 and IDH2 produce high levels of the R-enantiomer of 2-hydroxyglutarate (R-2HG), which is a competitive inhibitor of α-ketoglutarate (αKG)-dependent enzymes and a putative oncometabolite. Mutant IDH1 collaborates with HoxA9 to induce monocytic leukemia in vivo. We used two mouse models and a patient-derived acute myeloid leukemia xenotransplantation (PDX) model to evaluate the in vivo transforming potential of R-2HG, S-2HG and αKG independent of the mutant IDH1 protein. We show that R-2HG, but not S-2HG or αKG, is an oncometabolite in vivo that does not require the mutant IDH1 protein to induce hyperleukocytosis and to accelerate the onset of murine and human leukemia. Thus, circulating R-2HG acts in a paracrine manner and can drive the expansion of many different leukemic and preleukemic clones that may express wild-type IDH1, and therefore can be a driver of clonal evolution and diversity. In addition, we show that the mutant IDH1 protein is a stronger oncogene than R-2HG alone when comparable intracellular R-2HG levels are achieved. We therefore propose R-2HG-independent oncogenic functions of mutant IDH1 that may need to be targeted in addition to R-2HG production to exploit the full therapeutic potential of IDH1 inhibition.

RUNX1 mutations in acute myeloid leukemia are associated with distinct clinico-pathologic and genetic features.

We evaluated the frequency, genetic architecture, clinico-pathologic features and prognostic impact of RUNX1 mutations in 2439 adult patients with newly-diagnosed acute myeloid leukemia (AML). RUNX1 mutations were found in 245 of 2439 (10%) patients; were almost mutually exclusive of AML with recurrent genetic abnormalities; and they co-occurred with a complex pattern of gene mutations, frequently involving mutations in epigenetic modifiers (ASXL1, IDH2, KMT2A, EZH2), components of the spliceosome complex (SRSF2, SF3B1) and STAG2, PHF6, BCOR. RUNX1 mutations were associated with older age (16-59 years: 8.5%; ⩾60 years: 15.1%), male gender, more immature morphology and secondary AML evolving from myelodysplastic syndrome. In univariable analyses, RUNX1 mutations were associated with inferior event-free (EFS, P<0.0001), relapse-free (RFS, P=0.0007) and overall survival (OS, P<0.0001) in all patients, remaining significant when age was considered. In multivariable analysis, RUNX1 mutations predicted for inferior EFS (P=0.01). The effect of co-mutation varied by partner gene, where patients with the secondary genotypes RUNX1mut/ASXL1mut (OS, P=0.004), RUNX1mut/SRSF2mut (OS, P=0.007) and RUNX1mut/PHF6mut (OS, P=0.03) did significantly worse, whereas patients with the genotype RUNX1mut/IDH2mut (OS, P=0.04) had a better outcome. In conclusion, RUNX1-mutated AML is associated with a complex mutation cluster and is correlated with distinct clinico-pathologic features and inferior prognosis.

Prognostic implications and molecular associations of NADH dehydrogenase subunit 4 (ND4) mutations in acute myeloid leukemia.

To study the prevalence and prognostic importance of mutations in NADH dehydrogenase subunit 4 (ND4), a mitochondrial encoded transmembrane component of the electron transport chain respiratory Complex I, 452 AML patients were examined for ND4 mutations by direct sequencing. The prognostic impact of ND4 mutations was evaluated in the context of other clinical prognostic markers and genetic risk factors. In all, 29 of 452 patients (6.4%) had either somatic (n=12) or germline (n=17) ND4 mutations predicted to affect translation. Somatic mutations were more likely to be heteroplasmic (P<0.001), to occur in predicted transmembrane domains (P<0.001) and were predicted to have damaging effects upon translation (P<0.001). Patients with somatically acquired ND4 mutations had significantly longer relapse-free survival (P=0.017) and overall survival (OS) (P=0.021) than ND4(wildtype) patients. Multivariate analysis also demonstrated a tendency for increased survival in patients with somatic ND4 mutations (RFS: hazard ratio (HR) 0.25, confidence interval (CI) 0.06-1.01, P=0.052; OS: HR 0.29, CI 0.74-1.20, P=0.089). Somatic ND4(mutated) patients had a higher prevalence of concomitant DNMT3A mutations (P=0.023) and a higher percentage of the NPM1/FLT3-ITD low-risk genotype (P=0.021). Germline affected cases showed higher BAALC (P=0.036) and MLL5 (P=0.051) expression levels. Further studies are warranted to validate the favorable prognostic influence of acquired ND4 mutations in AML.

Prevalence and prognostic value of IDH1 and IDH2 mutations in childhood AML: a study of the AML-BFM and DCOG study groups.

Mutations in the NADP(+)-dependent isocitrate dehydrogenase genes 1 and 2 (IDH1 and IDH2) have recently been found in adult acute myeloid leukemia (AML) patients with a prevalence rising up to 33%. To investigate the frequency of IDH1/2 mutations in pediatric AML, we characterized the mutational hotspot (exon 4) of these genes in diagnostic samples from 460 pediatric AML patients. Our analysis identified somatic IDH1/2 mutations in 4% of cases (IDH1 R132 n=8; IDH2 R140 n=10) and the minor allele of single-nucleotide polymorphism (SNP) rs11554137 in 47 children (10.2%). IDH mutations were associated with an intermediate age (P=0.008), FAB M1/M2 (P=0.013) and nucleophosmin1 mutations (P=0.001). In univariate analysis, IDH(mutated) compared with IDH(wildtype) patients showed a significantly improved overall survival (OS; P=0.032) but not event-free survival (EFS; P=0.14). However, multivariate analysis did not show independent prognostic significance. Children with at least one minor allele of IDH1 SNP rs11554137 had similar EFS (P=0.27) and OS (P=0.62) compared with major allele patients. Gene expression profiles of 12 IDH(mutated) were compared with 201 IDH(wildtype) patients to identify differentially expressed genes and pathways. Although only a small number of discriminating genes were identified, analysis revealed a deregulated tryptophan metabolism, and a significant downregulation of KYNU expression in IDH(mutated) cases.