Allogeneic transplantation as post-remission therapy for cytogenetically high-risk acute myeloid leukemia: landmark analysis from a single prospective multicenter trial

Allogeneic hematopoietic cell transplantation for acute myeloid leukemia with hyperdiploid complex karyotype

Allogeneic hematopoietic cell transplantation (allo-HCT) remains the best consolidation strategy for acute myeloid leukemia (AML) with complex karyotype (CK). However, CK is a heterogenous and highly diverse entity. Numerical abnormalities have been associated with a controversial prognosis and AML with only multiple numerical abnormalities known as pure hyperdiploid karyotype (HDK) may have a distinct prognosis after allo-HCT compared to non-pure HDK CK AML. A total of 236 patients were identified within the EBMT registry as having HDK comprising 95 pure (pHDK) and 141 with other cytogenetic abnormalities (HDK+). The 2-year probability of leukemia-free survival (LFS) was 50% for pHDK and 31% for HDK+ (p = 0.003). The 2-year probability of overall survival (OS) was 57% for pHDK and 36% for HDK+ (p = 0.007). The 2-year cumulative incidence of relapse (RI) was 22% for pHDK and 44% for HDK+ (p = 0.001). The 2-year probability of graft-versus-host disease (GvHD)-free and relapse-free survival (GRFS) was 36% for pHDK and 21% for HDK+ (p = 0.01). On multivariate analysis, pHDK remained associated with significantly better LFS, OS and GRFS and lower RI (all p-values <0.004). pHDK AML constitutes probably a distinct cytogenetic entity from HDK+ or other non-hyperdiploid CK AML with better outcomes after allo-HCT.

What Influences the Decision to Proceed to Transplant for Patients With AML in First Remission?

Although allogeneic hematopoietic cell transplantation (allo-HCT) remains the backbone of curative treatment for the majority of fit adults diagnosed with AML, there is indeed a subset of patients for whom long-term remission may be achieved without transplantation. Remarkable changes in our knowledge of AML biology in recent years has transformed the landscape of diagnosis, management, and treatment of AML. Specifically, markedly increased understanding of molecular characteristics of AML, the expanded application of minimal/measurable residual diseases testing, and an increased armamentarium of leukemia-directed therapeutic agents have created a new paradigm for the medical care of patients with AML. An attempt is herein made to decipher the decision to proceed to transplant for patients with AML in first complete remission on the basis of the current best available evidence. The focus is on factors affecting the biology and treatment of AML itself, rather than on variables related to allo-HCT, an area characterized by significant advancements that have reduced overall therapy-related complications. This review seeks to focus on areas of particular complexity, while simultaneously providing clarity on how our current knowledge and treatment strategies may, or may not, influence the decision to pursue allo-HCT in patients with AML.

Haploidentical haematopoietic stem cell transplantation for TP53-mutated acute myeloid leukaemia

Acute myeloid leukaemia (AML) patients with tumour protein p53 (TP53) mutations are often resistant to chemotherapy and have worse clinical outcomes than patients without TP53 mutations. In this study, we compared clinical outcomes of patients with AML with and without TP53 mutations who underwent haploidentical haematopoietic stem cell transplantation (haplo-HSCT). For the TP53-mutation group and TP53 wild-type group, the 2-year cumulative incidence of relapse (CIR) was (39.0% vs. 21.2% respectively, p = 0.088), the 2-year non-relapse mortality (NRM) rate was (3.2% vs. 8.4% respectively, p = 0.370), the 2-year leukaemia-free survival (LFS) was (57.7% vs. 71.3% respectively, p = 0.205), the 2-year overall survival (OS) rate was (69.9% vs. 81.3% respectively, p = 0.317), the 100-day cumulative incidence of Grade II-IV acute graft-versus-host disease (GvHD) was (6.5% vs. 20.7% respectively, p = 0.074), the 2-year cumulative incidence of chronic GvHD was (52.3% vs. 53.1% respectively, p = 0.493) and the 2-year GvHD-free/relapse-free survival (GRFS) was (57.7% vs. 69.6% respectively, p = 0.347). Our data showed that there were no significant differences in 2-year clinical outcomes between the two groups. Multivariable analysis showed TP53 mutations had no significant impact on CIR, NRM, OS, GvHD, LFS or GRFS. Our findings suggest that patients with AML with TP53 mutations may at least partially benefit from haplo-HSCT. Haplo-HSCT might be the recommended treatment for such patients.

Predictors of outcomes in adults with acute myeloid leukemia and KMT2A rearrangements

Acute myeloid leukemia (AML) with rearrangement of the lysine methyltransferase 2a gene (KMT2Ar) has adverse outcomes. However, reports on the prognostic impact of various translocations causing KMT2Ar are conflicting. Less is known about associated mutations and their prognostic impact. In a retrospective analysis, we identified 172 adult patients with KMT2Ar AML and compared them to 522 age-matched patients with diploid AML. KMT2Ar AML had fewer mutations, most commonly affecting RAS and FLT3 without significant impact on prognosis, except for patients with ≥2 mutations with lower overall survival (OS). KMT2Ar AML had worse outcomes compared with diploid AML when newly diagnosed and at relapse, especially following second salvage (median OS of 2.4 vs 4.8 months, P < 0.0001). Therapy-related KMT2Ar AML (t-AML) had worse outcomes compared with de novo KMT2Ar AML (median OS of 0.7 years vs 1.4 years, P < 0.0001). Allogeneic hematopoietic stem cell transplant (allo-HSCT) in first remission was associated with improved OS (5-year, 52 vs 14% for no allo-HSCT, P < 0.0001). In a multivariate analysis, translocation subtypes causing KMT2Ar did not predict survival, unlike age and allo-HSCT. In conclusion, KMT2Ar was associated with adverse outcomes regardless of translocation subtype. Therefore, AML risk stratification guidelines should include all KMT2Ar as adverse.

Glasdegib as maintenance therapy for patients with AML and MDS patients at high risk for postallogeneic stem cell transplant relapse

Posttransplantation, glasdegib maintenance therapy in patients at high risk for relapse did not meaningfully reduce relapse incidence. Use of glasdegib in the posttransplantation setting was complicated by adverse events requiring drug holds and occasional discontinuation.

Prognostic impact of the adverse molecular-genetic profile on long-term outcomes following allogeneic hematopoietic stem cell transplantation in acute myeloid leukemia

The impact of adverse risk genetic profiles on outcomes in acute myeloid leukemia (AML) patients following allogeneic hematopoietic stem cell transplantation (HCT) has not been fully elucidated. Accordingly, we have profiled somatic mutations at diagnosis using next-generation sequencing (NGS) in 178 AML patients who received allogeneic HCT. NGS revealed 598 somatic mutations in 165/178 patients (92.7%). Frequently mutated genes include DNMT3A, TET2, NPM1, RUNX1, IDH2, and FLT3. Commonly detected cytogenetic profiles include normal karyotype, trisomy 8, monosomal karyotype (MK), deletion 5, complex karyotype (CK), and monosomy 7. In univariate analyses, TP53 mutation, MK, CK, and monosomy 7 were associated with decreased overall survival (OS), relapse-free survival (RFS), and a higher relapse incidence (RI). We defined adverse molecular-genetic profile as harboring at least one of the molecular/genetic abnormalities of TP53 mutation, MK, CK, monosomy 7, and deletion 5. The patients harboring adverse molecular-genetic profile (n = 30) showed a lower 2-year OS (24.9% vs. 57.9%; p = 0.003), RFS (23.7% vs. 57.9%; p = 0.002), and higher RI (47.2% and 17.2%; p = 0.001) after HCT when compared to patients without those lesions. Multivariate analysis confirmed adverse molecular-genetic profile as an independent prognostic factor, associated with decreased OS (HR 2.19), RFS (HR 2.23), and higher RI (HR 2.94).

The Clinical impact of PTPN11 mutations in adults with acute myeloid leukemia

While germline and somatic mutations in the gene PTPN11, encoding a phosphatase which regulates the RAS signaling pathway, are well characterized in children with Noonan syndrome and juvenile myelomonocytic leukemia, less is known about their clinical impact in adults with acute myeloid leukemia (AML). To elucidate the effect of PTPN11 mutations (PTPN11^mut) on clinical outcomes, we screened adult patients with AML treated at our institution using targeted next-generation sequencing. Among 1406 consecutive patients, 112 (8%) had PTPN11^mut. These mutations were more commonly associated with the acute myelomonocytic/monocytic leukemia subtype than was wild-type PTPN11, while none were detected in patients with core-binding factor AML. They co-occurred more commonly with NPM1 mutations and FLT3 internal tandem duplications and less commonly with mutations in IDH2 and a complex karyotype. Compared with the wild-type allele, PTPN11^mut was associated with lower complete response rates (54% vs 40%; P = 0.04), and shorter overall survival (median 13.6 vs 8.4 months; P = 0.008). In a multivariate analysis, PTPN11^mut independently increased the risk of death, with a hazard ratio of 1.69 (95% CI, 1.25-2.29; P = 0.0007). In summary, mutations in PTPN11 have a characteristic phenotype in adults with AML and are associated with an adverse prognosis.

Prednisolone poor response is not an indication for HSCT in pediatric B-cell precursor acute lymphoblastic leukemia in first remission: results from JACLS ALL-02 study

Approximately 90% of pediatric acute lymphoblastic leukemia (ALL) cases are curable with intensified chemotherapy, but very high-risk patients may require hematopoietic stem cell transplantation (HSCT). A suitable indication for HSCT in the first complete remission (CR1) should be defined to protect patients from long-term complications. We report the outcomes of HSCT in CR1 from the Japan Association of Childhood Leukemia Study (JACLS) ALL-02 study and reassess indications for HSCT. Of 1114 patients, 71 (6.4%) received HSCT in CR1. Indications included high-risk cytogenetic abnormalities and non-CR on day 33. Patients with B-cell precursor (BCP) ALL and a prednisolone poor response (PPR) received HSCT when leukocyte antigen-matched siblings were available. The 4-year overall survival (OS) of transplanted patients was 78.8% (confidence interval 67.3-86.6). Multivariate analysis revealed that cord blood transplantation was associated with poor OS. For BCP-ALL patients with PPR who achieved CR1 after induction therapy, HSCT in CR1 showed excellent outcomes (4-year OS 90.9%) but demonstrated no survival advantage as the outcome with chemotherapy was also excellent (4-year OS 97.0%). This study suggests that in BCP-ALL patients PPR is not an indication for HSCT in CR1. Precise evaluation of treatment responses would increase sophistication of indications for HSCT in CR1.

Hematopoietic Cell Transplantation in the Treatment of Newly Diagnosed Adult Acute Myeloid Leukemia: An Evidence-Based Review from the American Society of Transplantation and Cellular Therapy

The role of hematopoietic cell transplantation (HCT) in the management of newly diagnosed adult acute myeloid leukemia (AML) is reviewed and critically evaluated in this evidence-based review. An AML expert panel, consisting of both transplant and nontransplant experts, was invited to develop clinically relevant frequently asked questions covering disease- and HCT-related topics. A systematic literature review was conducted to generate core recommendations that were graded based on the quality and strength of underlying evidence based on the standardized criteria established by the American Society of Transplantation and Cellular Therapy Steering Committee for evidence-based reviews. Allogeneic HCT offers a survival benefit in patients with intermediate- and high-risk AML and is currently a part of standard clinical care. We recommend the preferential use of myeloablative conditioning in eligible patients. A haploidentical related donor marrow graft is preferred over a cord blood unit in the absence of a fully HLA-matched donor. The evolving role of allogeneic HCT in the context of measurable residual disease monitoring and recent therapeutic advances in AML with regards to maintenance therapy after HCT are also discussed.

Prognostic Impact of Cytogenetic Evolution on the Outcome of Allogeneic Stem Cell Transplantation in Patients with Acute Myeloid Leukemia in Nonremission: A Single-Institute Analysis of 212 Recipients

Recent progress in genetic analysis technology has helped researchers understand the pathogenesis of acute myeloid leukemia (AML). Considering this progress, AML karyotype is still one of the most significant prognostic factors that provides risk-adapted treatment approaches. Karyotype changes during treatment have been observed at times, but their prognostic impact is sparse, especially on allogeneic stem cell transplantation (allo-SCT). Here, we retrospectively investigated the effect of chromosomal changes between diagnosis and pretransplantation on the prognosis of allo-SCT by analyzing the outcomes of 212 consecutive patients who underwent allo-SCT for the first time at Toranomon Hospital, Tokyo, Japan, between 2008 and 2018. Cytogenetic abnormalities at diagnosis and pretransplantation were categorized based on the 2017 European Leukemia Net risk stratification. Genetic abnormalities such as FLT3-ITD and NPM1 were not considered in this study due to lack of genetic information in most patients. We defined cytogenetic evolution as chromosomal changes classified from lower category to higher category. Seventeen patients (8%) had cytogenetic evolution between diagnosis and pretransplantation, and they showed a significantly worse relapse rate than those who were categorized in the intermediate group based on the karyotype at diagnosis (3-year confidence interval [CI] of relapse, 57.4% versus 24.9%; P < .01). In multivariate analysis, cytogenetic evolution before allo-SCT had a significant impact on the CI of relapse (hazard ratio [HR], 3.89; CI, 1.75 to 8.67; P < .01), as well as the high score of the hematopoietic cell transplantation-specific comorbidity index (HR, 0.54; CI, 0.31 to 0.94; P = .03), but had no significant impact on overall survival or nonrelapse mortality. These results indicate that cytogenetic evolution has a significant impact after allo-SCT and should be considered during AML treatment.

The safety and effectiveness of genetically corrected iPSCs derived from β-thalassaemia patients in nonmyeloablative β-thalassaemic mice

BACKGROUND

β-Thalassaemia is a clinically common cause of hereditary haemolytic anaemia stemming from mutations in important functional regions of the β-globin gene. The rapid development of gene editing technology and induced pluripotent stem cell (iPSC)-derived haematopoietic stem cell (HSC) transplantation has provided new methods for curing this disease.

METHODS

Genetically corrected β-thalassaemia (homozygous 41/42 deletion) iPSCs that were previously established in our laboratory were induced to differentiate into HSCs, which were transplanted into a mouse model of IVS2-654 β-thalassaemia (B6;129P2-Hbb^tm2Unc/J mice) after administration of an appropriate nonmyeloablative conditioning regimen. We also investigated the safety of this method by detecting the incidence of tumour formation in these mice after transplantation.

RESULTS

The combination of 25 mg/kg busulfan and 50 mg/(kg day) cyclophosphamide is an ideal nonmyeloablative protocol before transplantation. Genetically corrected β-thalassaemic HSCs survived and differentiated in nonmyeloablated thalassaemia mice. No tumour formation was observed in the mice for 10 weeks after transplantation.

CONCLUSION

Our study provides evidence that the transplantation of genetically corrected, patient-specific iPSCs could be used to cure genetic diseases, such as β-thalassaemia major.

The impact of concomitant cytogenetic abnormalities on acute myeloid leukemia with monosomy 7 or deletion 7q after HLA-matched allogeneic stem cell transplantation

Monosomy 7 or deletion 7q (-7/7q-) is the most frequent adverse cytogenetic features reported in acute myeloid leukemia (AML), and is a common indication for allogeneic stem cell transplantation (SCT). Nevertheless, -7/7q- occurs frequently with other high-risk cytogenetic abnormalities such as complex karyotype (CK), monosomal karyotype (MK), monosomy 5 or deletion 5q (-5/5q-), 17p abnormalities (abn(17p)) or inversion of chromosome 3 (inv(3)), the presence of which may influence the outcomes after SCT. A total of 1109 patients were allocated to this study. Two-year probability of leukemia-free survival (LFS) and overall survival (OS) were 30% and 36%, respectively. Two-year probability of non-relapse mortality (NRM) was 20%. We defined five different cytogenetic subgroups: the "-7/7q- ± CK group- designated group1," the "MK group-designated group 2," the "-5/5q- group- designated group 3," the "abn(17p) group- designated group 4" and the "inv(3) group- designated group 5." The 2-year probability of LFS in first remission was 48% for group 1, 36.4% for group 2, 28.4% for group 3, 19.1% for group 4 and 17.3% for group 5, respectively (P < .001). Multivariate analysis confirmed those significant differences across groups. Note, SCT in -7/7q- AML provides durable responses in one third of the patients. The presence of -7/7q- with or without CK in the absence of MK, abn(17p) or inv(3) is associated with a better survival after SCT. On the contrary, addition of MK, -5/5q-, abn(17p) or inv(3) identifies a sub-group of patients with poor prognosis even after SCT.

Allogeneic stem cell transplantation using HLA-matched donors for acute myeloid leukemia with deletion 5q or monosomy 5: a study from the Acute Leukemia Working Party of the EBMT

Deletion 5q or monosomy 5 (-5/5q-) in acute myeloid leukemia (AML) is a common high-risk feature that is referred to allogeneic stem cell transplantation. However, -5/5q- is frequently associated with other high-risk cytogenetic aberrations such as complex karyotype, monosomal karyotype, monosomy 7 (-7), or 17p abnormalities (abn (17p)), the significance of which is unknown. In order to address this question, we studied adult patients with AML harboring -5/5q- having their first allogeneic transplantation between 2000 and 2015. Five hundred and one patients with -5/5q- have been analyzed. Three hundred and thirty-eight patients (67%) were in first remission and 142 (28%) had an active disease at time of allogeneic transplantation. The 2-year probabilities of overall survival and leukemia-free survival were 27% and 20%, respectively. The 2-year probability of treatment-related mortality was 20%. We identified four different cytogenetic groups according to additional abnormalities with prognostic impact: -5/5q- without complex karyotype, monosomal karyotype or abn(17p), -5/5q- within a complex karyotype, -5/5q- within a monosomal karyotype and the combination of -5/5q- with abn(17p). In multivariate analysis, factors associated with worse overall survival and leukemia-free survival across the four groups were active disease, age, monosomal karyotype, and abn(17p). The presence of -5/5q- without monosomal karyotype or abn(17p) was associated with a significantly better survival rate while -5/5q- in conjunction with monosomal karyotype or abn(17p) translated into a worse outcome. The patients harboring the combination of -5/5q- with abn(17p) showed very limited benefit from allogeneic transplantation.

Precision medicine and novel molecular target therapies in acute myeloid leukemia: the background of hematologic malignancies (HM)-SCREEN-Japan 01

The development of allogeneic hematopoietic-stem-cell transplantation has improved the prognosis of younger acute myeloid leukemia (AML) patients. However, the outcome of older AML patients remains poor. The majority of AML patients are elderly. For elderly AML patients unfit for intensive chemotherapy, less toxic single agent that targets a specific gene mutation or combination therapy with a single agent is needed. The role of chromosomal abnormalities and genetic mutations in leukemia has become more apparent, and detailed prognostic stratification based on the type of genetic mutation has been established. Next-generation sequencing (NGS) has been used for gene analysis of AML. In the future, the evaluation of biologically homogeneous population on the basis of chromosomal abnormalities and gene mutations will lead to a paradigm shift that will help in the development of optimized therapy. As rapid diagnosis of gene mutations is required by the clinical physicians to decide on induction therapy, it is important to have a swift turnaround time for comprehensive DNA sequencing to provide actionable data to clinical physicians. It is required to conduct a feasibility study to evaluate the turnaround time from sending the specimens to receiving the results while maintaining the quality of the specimens contributing to gene analysis. To detect infrequent gene mutations, investigators need to perform multicenter studies and/or cooperative-group trials with a certain sample size to examine the frequency of the gene mutations in elderly AML patients, enabling sufficient statistical power for meaningful comparisons.

Prolyl oligopeptidase inhibitor suppresses the upregulation of ACSDKP in patients with acute myeloid leukemia

The aim of the current study was to measure the expression of acetyl-N-Ser-Asp-Lys-Pro (ACSDKP) in patients with acute myeloid leukemia (AML) and the effect of prolyl oligopeptidase inhibitor (POPi) on the bone marrow stromal cells of these patients. Serum and bone marrow stromal cell samples were collected from 33 patients with AML admitted to Wuxi Second People's Hospital, Nanjing Medical University between September 2011 and August 2016. ACSDKP levels were measured using a highly specific competitive enzyme immunoassay (EIA). Bone marrow stromal cells were treated with synthetic ACSDKP (10 µM/ml) or different concentrations of POPi S17092 (25, 50 and 100 µg/ml). Cells that received no treatment were used as control. An MTT assay was conducted to measure the proliferation of bone marrow stromal cells. The results demonstrated that serum levels of ACSDKP in patients with AML were significantly higher than those of controls (P<0.05). Following treatment with ACSDKP, cell proliferation was significantly increased compared with untreated cells (P<0.05). However, following treatment with different concentrations of POPi, the expression of ACSDKP was significantly decreased in a dose-dependent manner (P<0.05). Furthermore, the proliferation of bone marrow stromal cells was also decreased in a dose-dependent manner. Therefore, the present study demonstrated that ACSDKP levels were increased in the serum and bone marrow stromal cells of patients with AML and that ACSDKP promoted the proliferation of bone marrow stromal cells of these patients, which was inhibited by POPi. These results may identify a novel target for the treatment of AML.

Allogeneic stem cell transplantation in adult patients with acute myeloid leukaemia and 17p abnormalities in first complete remission: a study from the Acute Leukemia Working Party (ALWP) of the European Society for Blood and Marrow Transplantation (EBMT)

BACKGROUND

Acute myeloid leukaemia (AML) with 17p abnormalities (abn(17p)) carries a very poor prognosis due to high refractoriness to conventional chemotherapy, and allogeneic stem cell transplantation (allo-SCT) appears as the only potential curative option.

METHODS

To address outcomes after allo-SCT in patients with abn(17p), we retrospectively analysed de novo or secondary AML undergoing SCT between 2000 and 2013 from the EBMT registry.

RESULTS

One hundred thirty-nine patients with confirmed abn(17p) have been selected. At the time of transplant, one hundred twenty-five were in first remission (CR1). Median age was 54 years old. Abn(17p) was associated with a monosomal karyotype in 83% of patients, complex karyotype in 91%, monosomy 5 or 5q deletion (-5/5q-) in 55%, monosomy 7 (-7) in 39% and both -5/5q and -7 in 27%. Seventy-three patients (59%) had a reduced-intensity conditioning regimen. The 2-year overall survival (OS) and leukaemia-free survival (LFS) were 28 and 24%, respectively. The 2-year non-relapse mortality (NRM) was 15%, and 2-year relapse incidence (RI) was 61%. The cumulative incidence of grade II to IV acute graft-versus-host disease (GvHD) was 24% and that of chronic GvHD was 21%. In multivariate analysis, the presence of a -5/5q- in addition to abn(17p) was significantly and independently associated with worse OS, LFS and higher RI. Age and donor types did not correlate with outcome. Conditioning intensity was not statistically associated with OS, LFS and NRM when adjusted for patients' age.

CONCLUSIONS

In contrast to the dismal prognosis reported for AML patients harbouring abn(17p) undergoing conventional chemotherapy, allogeneic SCT provides responses in about 25% of those patients transplanted in CR1.

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.

Molecular therapy for acute myeloid leukaemia

Acute myeloid leukaemia (AML) is a heterogeneous disease that is, in general, associated with a very poor prognosis. Multiple cytogenetic and molecular abnormalities that characterize different forms of AML have been used to better prognosticate patients and inform treatment decisions. Indeed, risk status in patients with this disease has classically been based on cytogenetic findings; however, additional molecular characteristics have been shown to inform risk assessment, including FLT3, NPM1, KIT, and CEBPA mutation status. Advances in sequencing technology have led to the discovery of novel somatic mutations in tissue samples from patients with AML, providing deeper insight into the mutational landscape of the disease. The majority of patients with AML (>97%) are found to have a clonal somatic abnormality on mutational profiling. Nevertheless, our understanding of the utility of mutation profiling in clinical practice remains incomplete and is continually evolving, and evidence-based approaches to application of these data are needed. In this Review, we discuss the evidence-base for integrating mutational data into treatment decisions for patients with AML, and propose novel therapeutic algorithms in the era of molecular medicine.

HLA mismatching as a strategy to reduce relapse after alternative donor transplantation

Human leukocyte antigen (HLA) mismatches are targets of alloreactive T cells, mediators of graft-versus-leukemia (GvL) and graft-versus-host disease (GvHD) after alternative donor transplantation. Exploitation of HLA mismatching in order to reduce relapse is hampered by necessary interventions aimed at controlling GvHD on the one hand, and by the possibility of immune escape through selective loss of mismatched HLA in relapsing leukemia on the other. Retrospective studies reporting the impact of HLA mismatches on post-transplant relapse need to be interpreted with caution, due to many confounding factors, including disease and use of T-cell depletion, and to be constantly updated to the rapidly changing clinical protocols. Current evidence suggests similar relapse rates for 8/8, 7/8 HLA-matched unrelated, T-cell-replete haploidentical and umbilical cord blood transplantation; however, investigations of locus-specific effects are still scarce in the latter two settings. In unrelated transplantation, a specific role for mismatches at HLA-C and HLA-DPB1, and therein of permissive mismatches defined on the basis of T-cell alloreactivity and/or expression levels, in reducing relapse has been demonstrated in independent studies. This observation suggests new approaches to utilize HLA matching in unrelated donor searches, and the need for further research in the field.

Single monosomy as a relatively better survival factor in acute myeloid leukemia patients with monosomal karyotype

Monosomal karyotype (MK) defined by either ⩾2 autosomal monosomies or single monosomy with at least one additional structural chromosomal abnormality is associated with a dismal prognosis in patients with acute myeloid leukemia (AML). It was detected in 174 of 3041 AML patients in South Korean Registry. A total of 119 patients who had received induction therapy were finally analyzed to evaluate the predictive factors for a positive prognosis. On multivariate analysis, single monosomy, the absence of abn(17p), ⩾10% of cells with normal metaphase and the achievement of a complete remission (CR) after induction therapy were significant factors for more favorable outcomes. Especially, single monosomy remained as a significantly independent prognostic factor for superior survival in both patients who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) in CR and who did not. Allo-HSCT in CR improved overall survival significantly only in patients with a single monosomy. Our results suggest that MK-AML may be biologically different according to the karyotypic subtype and that allo-HSCT in CR should be strongly recommended to patients with a single monosomy. For other patients, more prudent treatment strategies should be examined. Furthermore, the biological mechanism by which a single monosomy influences survival should be investigated.

Assessing the efficacy of allogeneic hematopoietic stem cells transplantation (allo-HSCT) by analyzing survival end points in defined groups of acute myeloid leukemia patients: a retrospective, multicenter Polish Adult Leukemia Group study

The importance of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for survival outcomes in patients with acute myeloid leukemia (AML) currently remains unclear. The study aimed to compare measures of clinical treatment for patients with AML in CR1 (the first complete remission) with or without being subjected to allo-HSCT. These consisted of leukemia-free survival (LFS), overall survival (OS), cumulative incidence of relapse (CIR), and non-relapse mortality disease (NRM). Subjects were 622 patients, median age of 44, forming part of the prospective, randomized, and multicenter clinical Polish Adult Leukemia Group trials during 1999-2008. The Mantel-Byar approach was used to assess allo-HSCT on survival endpoints, accounting for a changing transplant status. Undergoing allo-HSCT significantly improved the LFS and OS for the entire group of patients with AML in CR1, along with the DAC induction subgroup and for the group with unfavorable cytogenetics aged 41-60. The CIR demonstrated that allo-HSCT reduced the risk of relapse for patients with AML in CR1 and those with an unfavorable cytogenetic risk. In addition, the NRM analysis showed that allo-HSCT significantly reduced the risk of death unrelated to relapse for the entire group of AML patients in CR1 and aged 41-60. The allo-HSCT treatment particularly benefitted survival for the AML in CR1 group having an unfavorable cytogenetic prognosis.

Outcome of conditioning intensity in acute myeloid leukemia with monosomal karyotype in patients over 45 year-old: A study from the acute leukemia working party (ALWP) of the European group of blood and marrow transplantation (EBMT)

Acute myeloid leukemia with monosomal karyotype (MK AML) carries a very poor prognosis, even after allogeneic stem cell transplantation (SCT). However, SCT remains the only curative option in this high-risk population. Because myeloablative conditioning regimen (MAC) is associated with less relapse, we hypothesized that more intensive conditioning regimen might be beneficial for MK AML patients. We reviewed 303 patients over age 45 diagnosed with either de novo or secondary MK AML. One hundred and five patients received a MAC and 198 a reduced-intensity conditioning (RIC). The median age at SCT was 57-year-old, significantly lower in the MAC (53-year-old) than in the RIC group (59-year-old). The median follow-up was 42 months (range, 3 - 156 months). The 3-year overall survival (OS), leukemia-free survival (LFS), and relapse rate (RR) were not significantly different between both groups with overall values of 34%, 29%, and 51%, respectively. On the contrary, the 3-year nonrelapse mortality (NRM) was significantly higher in MAC recipients (28%) compared with RIC patients (16%, P = 0.004). The incidence of Grades II to IV acute graft-versus-host disease (GvHD) was significantly higher after a MAC (30.5%) than after a RIC (19.3%, P = 0.02). That of chronic GvHD was comparable between both groups (35%) and did not impact on LFS. Interestingly, within our MK AML cohort, hypodiploidy was significantly associated with worse outcomes. Due to reduced toxicity and comparable OS, LFS, and RR, RIC appears as a good transplant option in the very high-risk population, including older patients, diagnosed with MK AML.

Efficacy of Allogeneic Hematopoietic Stem Cell Transplantation in Intermediate-Risk Acute Myeloid Leukemia Adult Patients in First Complete Remission: A Meta-Analysis of Prospective Studies

Hematopoietic stem cell transplantation (HSCT) and consolidation chemotherapy have been used to treat intermediate-risk acute myeloid leukemia (AML) patients in first complete remission (CR1). However, it is still unclear which treatments are most effective for these patients. The aim of our study was to analyze the relapse-free survival (RFS) and overall survival (OS) benefit of allogeneic HSCT (alloHSCT) for intermediate-risk AML patients in CR1. A meta-analysis of prospective trials comparing alloHSCT to non-alloHSCT (autologous HSCT [autoHSCT] and/or chemotherapy) was undertaken. We systematically searched PubMed, Embase, and the Cochrane Library though October 2014, using keywords and relative MeSH or Emtree terms, 'allogeneic'; 'acut*' and 'leukem*/aml/leukaem*/leucem*/leucaem*'; and 'nonlympho*' or 'myelo*'. A total of 7053 articles were accessed. The primary outcomes were RFS and OS, while the secondary outcomes were treatment-related mortality (TRM) and relapse rate (RR). Hazard ratios (HR) and 95% confidence intervals (CI) were calculated for each outcome. The primary outcomes were RFS and OS, while the secondary outcomes were TRM and RR. We included 9 prospective controlled studies including 1950 adult patients. Patients with intermediate-risk AML in CR1 who received either alloHSCT or non-alloHSCT were considered eligible. AlloHSCT was found to be associated with significantly better RFS, OS, and RR than non-alloHSCT (HR, 0.684 [95% CI: 0.48, 0.95]; HR, 0.76 [95% CI: 0.61, 0.95]; and HR, 0.58 [95% CI: 0.45, 0.75], respectively). TRM was significantly higher following alloHSCT than non-alloHSCT (HR, 3.09 [95% CI: 1.38, 6.92]). However, subgroup analysis showed no OS benefit for alloHSCT over autoHSCT (HR, 0.99 [95% CI: 0.70, 1.39]). In conclusion, alloHSCT is associated with more favorable RFS, OS, and RR benefits (but not TRM outcomes) than non-alloHSCT generally, but does not have an OS advantage over autoHSCT specifically, in patients with intermediate-risk AML in CR1.

Optimal therapy for adult patients with acute myeloid leukemia in first complete remission

Although it is absolutely clear that postremission therapy is currently necessary to obtain disease-free long-term survivorship for patients with acute myeloid leukemia (AML) in first complete remission (CR), it is not entirely clear what form that treatment should take. High-dose cytarabine is clearly effective and there definitely is a dose-response relationship for cytarabine and remission duration. High-dose cytarabine is effective for younger patients but not elderly patients. It is effective for patients with favorable cytogenetics but it is not clear whether it is effective for patients with intermediate or unfavorable cytogenetics. Furthermore, it is not clear what the most effective and least toxic dose and schedule of high-dose cytarabine is.

Treatment strategies in patients with AML or high-risk myelodysplastic syndrome relapsed after Allo-SCT

Non-relapse mortality after Allo-SCT has significantly decreased over the last years. Nevertheless, relapse remains a major cause for post SCT mortality in patients with AML and high-risk myelodysplastic syndrome (MDS). In this retrospective single-center analysis, we have analyzed the treatment outcomes of 108 patients with AML or MDS, who relapsed after Allo-SCT. Seventy of these patients (65%) were treated with salvage therapies containing chemotherapy alone, allogeneic cell-based treatment or the combination of both. Thirty-eight patients (35%) received palliative treatment. Median OS after diagnosis of relapse was 130 days. Compared with patients who received chemotherapy alone, response to salvage therapy was significantly improved in patients treated with a combination of chemo- and allogeneic cell-based therapy (CR rate 57% vs 13%, P=0.002). Among risk factors concerning pretreatment characteristics, disease status before first Allo-SCT, and details of transplantation, only the time interval from Allo-SCT to relapse was an independent predictor of response to salvage therapy and OS. These data confirmed that time to relapse after transplantation is an important prognostic factor. Up to now, only patients eligible for treatment regimens containing allogeneic cell-based interventions achieved relevant response rates.

Monosomal karyotype in acute myeloid leukemia and the role of allogeneic hematopoietic cell transplantation

Monosomal karyotype (MK) in acute myeloid leukemia (AML) is associated with an extremely poor outcome. The clinical significance of MK and the role of allogeneic hematopoietic cell transplantation (HCT) were evaluated in 749 Korean patients with newly diagnosed AML. MK was found in 9.3% of patients and was more frequent in patients with advanced age or secondary AML. Patients with MK had significantly lower blood leukocyte counts and bone marrow blast percentages, and they had lower complete remission (CR) rate (43%) and shorter median overall survival (OS) (6.5 months) and relapse-free survival (RFS) (10.0 months) than any other prognostic group. MK+ patients who received allogeneic HCT at the first CR had higher OS [hazard ratio (HR) 0.344, P = 0.018], RFS (HR 0.257, P = 0.006), and lower relapse probability (HR 0.264, P = 0.008) than those not receiving. This study's results confirmed poor outcomes for AML patients with MK and suggest that allogeneic HCT at the first CR may improve outcome.

Outcomes of allogeneic hematopoietic cell transplantation in acute myeloid leukemia patients with monosomal karyotypes

This study investigated the outcomes of allogeneic hematopoietic cell transplantation (allo-HCT) in acute myeloid leukemia (AML) patients with monosomal karyotypes (MK). A total of 114 AML patients who received allo-HCT were retrospectively analyzed. At the time of diagnosis, 13 patients were categorized with a favorable cytogenetic risk, 78 with an intermediate risk, and 23 with an adverse risk. MK was found in 12 patients among 23 with adverse cytogenetic risk. Pretransplant disease status was active disease in 5 cases (45.5%) in the adverse-risk without MK group, and 8 cases (66.7%) in the corresponding group with MK, 15 (19.2%) in the intermediate group and 4 (30.8%) in the favorable group. In multivariate analysis, active disease before transplant (hazard ratio, HR 3.913, p < 0.001), acute graft-versus-host disease (GVHD) ≥grade 2 (HR 1.908, p = 0.048) and chronic GVHD (HR 0.364, p = 0.001) affected overall survival (OS). The initial cytogenetic risk groups were not a significant risk factor for OS in allogeneic settings. The 2-year OS rate was 44.0 ± 15.9% without MK and 20.7 ± 17.9% with MK (p = 0.246). However, the OS rate was better for patients with chronic GVHD (p = 0.025). In conclusion, a survival benefit was observed for MK-positive patients with chronic GVHD in an allogeneic setting. However, the prognosis still remained poor for patients with MK.

Allogeneic hematopoietic cell transplantation for acute myeloid leukemia during first complete remission: a clinical perspective

Allogeneic hematopoietic cell transplantation (HCT) is the most potent therapy for preventing relapse of acute myeloid leukemia (AML). Although its efficacy is compromised by a high risk of treatment-related morbidity and mortality, an accumulating body of evidence has led to the general recommendation favoring allogeneic HCT from a matched sibling donor during first complete remission (CR1) for younger patients with cytogenetically intermediate- or high-risk AML. Over the past few decades, this field has seen a great many advancements. The indications for allogeneic HCT have been refined by taking into account the molecular profiles of leukemic cells and the degree of comorbidities. The introduction of high-resolution human leukocyte antigen-typing technology and advances in immunosuppressive therapy and supportive care measures have improved outcomes in alternative donor transplantation, while the parallel growth of unrelated donor registries and greater use of umbilical cord blood and haploidentical donors have considerably improved the chance of finding an alternative donor. The development of reduced-intensity and non-myeloablative conditioning has made it possible to receive allogeneic HCT for patients who might once have been considered ineligible due to advanced age or comorbidities. Thanks to these advances, the role of allogeneic HCT during CR1 has become progressively more important in the treatment of AML.

Inching toward cure of acute myeloid leukemia: a summary of the progress made in the last 50 years

Despite some claims to the contrary, I believe substantial progress has been made in the last half century toward cure of acute myeloid leukemia in children and adults. The tried and true mechanism for this progress has been clinical trial and error. This method has been supplemented with an ever-increasing amount of work at the clinical laboratory interface that is beginning to allow us to develop specific therapy for afflicted individuals. This review details where we stand today and how we got here.

Allogeneic hematopoietic cell transplantation may alleviate the negative prognostic impact of monosomal and complex karyotypes on patients with acute myeloid leukemia

Monosomal karyotype (MK) and complex karyotype (CK) are well known to be associated with a very poor clinical outcome in patients with acute myeloid leukemia (AML). However, whether or not the prognostic impact of MK and CK remains relevant for patients who have undergone allogeneic hematopoietic cell transplantation (allo-HCT) is still unclear. We retrospectively analyzed the status of MK and CK, as well as other clinical laboratory features, in 148 allo-HCT AML patients at our institution and correlated with their event-free survival (EFS) and overall survival (OS) after transplantation. MK and CK were identified in 14 (9%) and 19 (13%) cases, respectively. On univariate analysis, only age (≥60 years) and WBC count (≥15 × 10(9)/L) were significant adverse predictors for EFS (P < .001 and P = .017, respectively) and OS (P = .002 and P = .021, respectively). MK, CK, and other relevant parameters analyzed did not affect the clinical outcome. Multivariable analysis confirmed that both older age and high WBC count were independent prognostic factors for a shorter OS (P = .001 and P = .003, respectively) and a shorter EFS (P < .001 and P = .001, respectively). Our results indicate that neither MK nor CK are high-risk factors in AML patients undergoing allo-HCT.

Allogeneic transplantation versus chemotherapy as postremission therapy for acute myeloid leukemia: a prospective matched pairs analysis

PURPOSE

The majority of patients with acute myeloid leukemia (AML) who achieve complete remission (CR) relapse with conventional postremission chemotherapy. Allogeneic stem-cell transplantation (alloSCT) might improve survival at the expense of increased toxicity. It remains unknown for which patients alloSCT is preferable.

PATIENTS AND METHODS

We compared the outcome of 185 matched pairs of a large multicenter clinical trial (AMLCG99). Patients younger than 60 years who underwent alloSCT in first remission (CR1) were matched to patients who received conventional postremission therapy. The main matching criteria were AML type, cytogenetic risk group, patient age, and time in first CR.

RESULTS

In the overall pairwise compared AML population, the projected 7-year overall survival (OS) rate was 58% for the alloSCT and 46% for the conventional postremission treatment group (P = .037; log-rank test). Relapse-free survival (RFS) was 52% in the alloSCT group compared with 33% in the control group (P < .001). OS was significantly better for alloSCT in patient subgroups with nonfavorable chromosomal aberrations, patients older than 45 years, and patients with secondary AML or high-risk myelodysplastic syndrome. For the entire patient cohort, postremission therapy was an independent factor for OS (hazard ratio, 0.66; 95% CI, 0.49 to 0.89 for alloSCT v conventional chemotherapy), among age, cytogenetics, and bone marrow blasts after the first induction cycle.

CONCLUSION

AlloSCT is the most potent postremission therapy for AML and is particularly active for patients 45 to 59 years of age and/or those with high-risk cytogenetics.

Cytogenetic risk grouping by the monosomal karyotype classification is superior in predicting the outcome of acute myeloid leukemia undergoing allogeneic stem cell transplantation in complete remission

We retrospectively analyzed the impact of cytogenetic abnormalities grouped according to the monosomal karyotype (MK) classification or the Southwest Oncology/Eastern Cooperative Oncology Group (SWOG/ECOG) definition in 263 patients with acute myeloid leukemia (AML) who underwent allogeneic stem cell transplantation (alloSCT) in complete remission (CR) at our center. Risk grouping using the MK criteria shows a highly significant difference in 5-yr overall survival (OS) ranging between 67%, for the most favorable, and 32%, for the poorest risk group (P = 0.001). Although similarly precise in predicting OS, the MK scheme better separates patients with respect to relapse incidence as compared to the SWOG/ECOG grouping (P = 0.0001 vs. P = 0.01). Notably, patients displaying non-MK abnormalities (MK-) had a 5-yr relapse incidence identical to those cytogenetically normal (CN), that is 24%. Multivariate analysis revealed that the MK classification is an independent prognosticator and superior in predicting OS (hazard ratios, HR 3.74, P = 0.01) and relapse incidence (HR 3.74, P = 0.005) as compared to the SWOG/ECOG criteria. Finally, subgroup analysis revealed that the prognostic capacity of the MK classification is highly significant in patients treated with standard myeloablative conditioning prior to alloSCT (P = 0.0011 for OS, P = 0.0007 for relapse). In contrast, the MK grouping failed to predict OS or relapse incidence in patients treated with reduced intensity conditioning. Taken together, these results indicate that the MK classification is superior in predicting the overall outcome of patients with AML undergoing alloSCT in CR. Furthermore, our data suggest that the genetic risk profile of MK- and CN patients is mostly overlapping in this setting.

Clonal heterogeneity as detected by metaphase karyotyping is an indicator of poor prognosis in acute myeloid leukemia

PURPOSE

In acute myeloid leukemia (AML), studies based on whole-genome sequencing have shown genomic diversity within leukemic clones. The aim of this study was to address clonal heterogeneity in AML based on metaphase cytogenetics.

PATIENTS AND METHODS

This analysis included all patients enrolled onto two consecutive, prospective, randomized multicenter trials of the Study Alliance Leukemia. Patients were newly diagnosed with non-M3 AML and were fit for intensive chemotherapy.

RESULTS

Cytogenetic subclones were detected in 418 (15.8%) of 2,639 patients from the whole study population and in 418 (32.8%) of 1,274 patients with aberrant karyotypes. Among those, 252 karyotypes (60.3%) displayed a defined number of distinct subclones, and 166 (39.7%) were classified as composite karyotypes. Subclone formation was particularly frequent in the cytogenetically adverse group, with subclone formation in 69.0%, 67.1%, and 64.8% of patients with complex aberrant, monosomal, and abnl(17p) karyotypes (P < .001 each). Two-subclone patterns typically followed a mother-daughter evolution, whereas for ≥ three subclones, a branched pattern prevailed. In non-core binding factor AML, subclone formation was associated with inferior event-free and overall survival and was confirmed as an independent predictor of poor prognosis in multivariate analysis. Subgroup analysis showed that subclone formation adds prognostic information particularly in the cytogenetic adverse-risk group. Allogeneic stem-cell transplantation improved the prognosis of patients with subclone karyotypes as shown in landmark analyses.

CONCLUSION

Cytogenetic subclones are frequent in AML and permit tracing of clonal evolution and architecture. They bear prognostic significance with clonal heterogeneity as an independent adverse prognostic marker in cytogenetically adverse-risk AML.

Update on optimal management of acute myeloid leukemia

Acute myeloid leukemia (AML) represents a malignant accumulation of immature myeloid cells in the marrow, presenting with impaired hematopoiesis and its attendant complications, including bleeding, infection, and organ infiltration. Chromosomal abnormalities remain the most powerful predictors of AML prognosis and help to identify a subgroup with favorable prognosis. However, the majority of AML patients who are not in the favorable category succumb to the disease. Therefore, better efforts to identify those patients who may benefit from more aggressive and investigational therapeutic approaches are needed. Newer molecular markers aim at better characterizing the large group of intermediate-risk patients and to identify newer targets for therapy. A group that has seen little improvement over the years is the older AML group, usually defined as age ≥ 60. Efforts to develop less intensive but equally efficacious therapy for this vulnerable population are underway.

Expanded indications for allogeneic stem cell transplantation in patients with myeloid malignancies

PURPOSE OF REVIEW

Hematopoietic stem cell transplantation (SCT) can be curative for myeloid malignancies such as acute myeloid leukemia (AML). Advancements in human leukocyte antigen (HLA) typing and supportive care have improved the risk-benefit ratio for SCT, expanding its indications.

RECENT FINDINGS

Allogeneic SCT is an established treatment for AML with intermediate-risk and high-risk cytogenetics in first complete remission (CR1), from matched related donors (MRDs). Similar survival benefits are seen for AML in CR1 with unfavorable cytogenetics using matched unrelated donors (URDs). Molecular characterization has delineated patients with AML at higher risk with normal cytogenetics [e.g., FLT3-internal tandem duplication (ITD)+]. The outcomes of allogeneic SCT are comparable in patients with therapy-related or de-novo AML when adjusted for disease status and cytogenetics. In patients lacking a MRD, the majority will have a suitable alternative using an URD, umbilical cord blood, or haploidentical-related donors; outcomes are either comparable or relatively acceptable compared to a matched sibling donor. Comorbidity indices aid in identifying elderly and debilitated patients who may benefit from SCT; the application of SCT has been further increased by reduced-intensity conditioning regimens.

SUMMARY

Allogeneic SCT may be extended to almost all patients with AML, and integration of toxicity and relapse risks will determine the best approach for allogeneic SCT in the future.

High-Dose Cytarabine Consolidation With or Without Additional Amsacrine and Mitoxantrone in Acute Myeloid Leukemia: Results of the Prospective Randomized AML2003 Trial

Purpose

To assess the treatment outcome benefit of multiagent consolidation in young adults with acute myeloid leukemia (AML) in a prospective, randomized, multicenter trial.

Patients and Methods

Between December 2003 and November 2009, 1,179 patients (median age, 48 years; range, 16 to 60 years) with untreated AML were randomly assigned at diagnosis to receive either standard high-dose cytarabine consolidation with three cycles of 18 g/m2 (3× HD-AraC) or multiagent consolidation with two cycles of mitoxantrone (30 mg/m2) plus cytarabine (12 g/m2) and one cycle of amsacrine (500 mg/m2) plus cytarabine (10 g/m2; MAC/MAMAC/MAC). Allogeneic and autologous hematopoietic stem-cell transplantations were performed in a risk-adapted and priority-based manner.

Results

After double induction therapy using a 3 + 7 regimen including standard-dose cytarabine and daunorubicin, complete remission was achieved in 65% of patients. In the primary efficacy population of patients evaluable for consolidation outcomes, consolidation with either 3× HD-AraC or MAC/MAMC/MAC did not result in any significant difference in 3-year overall (69% v 64%; P = .18) or disease-free survival (46% v 48%; P = .99) according to the intention-to-treat analysis. Furthermore, MAC/MAMAC/MAC led to additional GI and hepatic toxicity and a higher rate of infection and bleeding, resulting in significantly shorter 3-year overall survival in the per-protocol analysis compared with 3× HD-AraC (63% v 72%; P = .04).

Conclusion

In younger adults with AML, multiagent consolidation using mitoxantrone and amsacrine in combination with high-dose cytarabine does not improve treatment outcome and confers additional toxicity.

CD34(+) lineage specific donor cell chimerism for the diagnosis and treatment of impending relapse of AML or myelodysplastic syndrome after allo-SCT

After allo-SCT, analysis of CD34(+) lineage-specific donor cell chimerism (DCC) is a sensitive method for monitoring minimal residual disease in patients with AML or myelodysplastic syndrome (MDS) with CD34 expression. To substantiate evidence of whether immune interventions in patients with impending relapse, defined by incomplete lineage-specific DCC, may prevent hematological relapse, we performed a retrospective nested case control study. Unsorted and lineage-specific DCC were measured in 134 patients. Forty-three patients had an incomplete CD34(+)-DCC with no other evidence of relapse. After immediate tapering of immunosuppressive treatment (30 patients) and/or infusion of donor lymphocytes (10 patients), 21 patients remained in remission (conversion to complete lineage-specific DCC) and 22 relapsed. Relapse-free survival at 3 years of the 91 patients with stable DCC and of the 43 patients with incomplete DCC was 74% (95% confidence interval (CI), 64-83%) and 40% (95% CI, 24-58%), respectively. OS rates were 79% (95% CI, 70-88%) and 52% (95% CI, 35-69%), respectively. These results, with 49% of patients with impending relapse successfully treated with immune intervention, highly suggest that analysis of CD34(+)-DCC is an important tool for monitoring and the management of AML and MDS patients after allo-SCT.

The European LeukemiaNet AML Working Party consensus statement on allogeneic HSCT for patients with AML in remission: an integrated-risk adapted approach

Allogeneic haematopoietic stem-cell transplantation (HSCT) is frequently applied as part of the treatment in patients with acute myeloid leukaemia (AML) in their first or subsequent remission. Allogeneic HSCT reduces relapse, but nonrelapse mortality and morbidity might counterbalance this beneficial effect. Here, we review recent studies reporting new disease-specific prognostic markers, in addition to allogeneic-HSCT-related risk factors, which can be assessed at specific time points during treatment. We propose risk assessment as a dynamic process during treatment, incorporating both disease-related and transplant-related factors for the decision to proceed either to allogeneic HSCT or to apply a nontransplant strategy. We suggest that allogeneic HSCT might be favoured if the projected disease-free survival is expected to improve by at least 10% based on an individual's risk assessment. The approach requires initial disease risk assessment, identifying a sibling or unrelated donor soon after diagnosis and the incorporation of time-dependent risk factors, all within the context of an integrated therapeutic management approach.

Comparative analysis of the value of allogeneic hematopoietic stem-cell transplantation in acute myeloid leukemia with monosomal karyotype versus other cytogenetic risk categories

PURPOSE

To determine to what extent allogeneic hematopoietic stem-cell transplantation (alloHSCT) quantitatively reduces relapse in acute myeloid leukemia with monosomal karyotype (MK-AML) compared with alternative postremission therapy and how it compares with other cytogenetic subcategories.

PATIENTS AND METHODS

Of 2,560 patients (younger than age 61 years) without core-binding factor abnormalities including 305 patients with MK-AML receiving first-line induction treatment, 1,975 patients (77%) achieved remission, and 1,588 received consolidation in the first complete remission (CR1) after two induction cycles. Consolidation treatment of 107 patients with MK-AML consisted of alloHSCT (n = 45), chemotherapy (n = 48), or autologous HSCT (n = 14).

RESULTS

The 5-year overall survival after start of consolidation was 19% for patients with MK-AML who received alloHSCT and 9% for those who received chemotherapy or autoHSCT (P = .02). Relapse-free survival (RFS) at 5 years was 17% versus 7% (P = .003). Cox regression analysis was performed with alloHSCT as a time-dependent covariate. Hazard ratios (HRs) associated with alloHSCT for relapse and RFS were 0.30 (95% CI, 0.24 to 0.37; P < .001), and 0.52 (95% CI, 0.43 to 0.62; P < .001), respectively. HRs were similar in MK-AML and the other cytogenetic subgroups.

CONCLUSION

AlloHSCT, applied as consolidation in CR1, is associated with a significant reduction of relapse and improvement of survival in MK-AML, with the same relative reduction of relapse or death as in other cytogenetic risk categories.