Allogeneic hematopoietic stem cell transplantation could improve survival of cytogenetically normal adult acute myeloid leukemia patients with DNMT3A mutations

DNMT3A mutations are frequent in cytogenetically normal acute myeloid leukemia (cn‐AML) patients and associated with poor survival. The role of allogeneic hematopoietic stem cell transplantation (allo‐HSCT) in DNMT3A^mut cn‐AML patients remains unclear. In this study, we retrospectively analyzed the prognostic impact of DNMT3A mutations and explored the role of allo‐HSCT in 308 cn‐AML patients who received consolidation of intensive chemotherapy or allo‐HSCT in our center from March 2005 to May 2014. In the whole cohort, 63 patients (20.5%) were identified with DNMT3A exon 23 mutations and R882H was the most frequent variant. DNMT3A^mut patients had shorter overall survival (3‐year OS: 31.9% vs. 52.0%, P = 0.009) and disease‐free survival (3‐year DFS: 21.8% vs. 40.1%, P = 0.004) compared with DNMT3A^wt patients. Based on FLT3/NPM1/CEBPA mutations, 308 cn‐AML patients were divided into favorable/intermediate group (n = 262) and unfavorable group (n = 46). There were no significant differences in 3‐year OS and 3‐year DFS between DNMT3A^mut and DNMT3A^wt patients in both favorable/intermediate and unfavorable groups. Additionally, in multivariate analysis, DNMT3A mutation remained an independent adverse prognostic factor for the survival. In the DNMT3A^mut cohort, 23 complete remission (CR) patients received allo‐HSCT consolidation and 32 CR patients received chemotherapy consolidation, dramatic differences were observed in 3‐year OS (51.7% vs. 28.9%, P = 0.048) and 3‐year DFS (41.6% vs. 14.9%, P = 0.024) between allo‐HSCT group and chemotherapy group. Collectively, DNMT3A mutation is a poor prognostic factor for cn‐AML patients and allo‐HSCT could improve survival of cn‐AML patients with DNMT3A mutations. Am. J. Hematol. 90:992–997, 2015. © 2015 Wiley Periodicals, Inc.     

Mild chronic graft‐versus‐host disease may alleviate poor prognosis associated with FLT3 internal tandem duplication for adult acute myeloid leukemia following allogeneic stem cell transplantation with myeloablative conditioning in first complete remission: a retrospective study

Internal tandem duplication (ITD) of the FLT3 gene (Fms‐like tyrosine kinase 3) is the most commonly found mutation in acute myeloid leukemia (AML). The significance of FLT3‐ITD at diagnosis was retrospectively estimated for allo‐HSCT (allogeneic hematopoietic stem cell transplantation) outcomes in 140 patients, median age of 38, undergoing allo‐HSCT after myeloablative conditioning in first complete remission of AML. FLT3‐ITD was detected at AML diagnosis in 42/140 (30%) of included into this study patients. At 3 years, relapse incidence (RI) following allo‐HSCT in AML patients with intermediate or normal karyotype was significantly higher in those FLT3‐ITD positive than FLT3‐ITD negative [52.9 vs. 20.4%, P = 0.002]. Additionally, patients with mild chronic graft‐versus‐host disease (cGvHD) had significantly lower RI compared to patients with moderate or severe grade cGvHD or those not experiencing cGvHD, respectively, 4.8 vs. 36.0 vs. 27.8%, P = 0.032. FLT3‐ITD was harboring a poor prognosis in AML with intermediate or normal karyotype and significantly increased risk of relapse following allo‐HSCT. It appears that allo‐HSCT does not cure patients with FLT3‐ITD, unless they develop symptoms of mild cGvHD and graft versus leukemia, which may decrease RI.     

The genotype nucleophosmin mutated and FLT3‐ITD negative is characterized by high bax/bcl‐2 ratio and favourable outcome in acute myeloid leukaemia

Nucleophosmin gene (NPM1) mutations characterize acute myeloid leukaemia (AML) with normal karyotype and frequently co‐exist with FLT3 internal tandem duplications (ITD). We evaluated bcl‐2, bax, NPM1 and FLT3‐ITD in 222 AML patients. Bax/bcl‐2 ratio >0·35 and NPM1 without FLT3‐ITD were significantly associated (P = 0·0001). NPM1‐mutated (mt)/FLT3‐ITD negative patients showed a higher complete remission (CR) rate (90%, P = 0·0002) and a longer overall survival (OS, P = 0·00007). NPM1‐mt/FLT3‐ITD negative plus bax/bcl‐2 > 0·35 subset showed a very high CR rate (96%), very long OS (P = 0·00005) and disease‐free survival (P = 0·004). The favourable prognosis of NPM1‐mt/FLT3‐ITD negative patients might be explained by a higher bax/bcl‐2 ratio.     

The FLT3ITD mRNA level has a high prognostic impact in NPM1 mutated, but not in NPM1 unmutated, AML with a normal karyotype

The impact of a FLT3-internal tandem duplication (FLT3ITD) on prognosis of patients with acute myeloid leukemia (AML) is dependent on the ratio of mutated to wild-type allele. In 648 normal karyotype (NK) AML patients, we found a significant independent effect of the quantitative FLT3ITD mRNA level--measured as (FLT3ITD/wtFLT3)/(FLT3ITD/wtFLT3+1)--on outcome. Moreover, this effect was clearly seen in 329 patients with a mutated NPM1 gene (NPM1+), but not in 319 patients without a NPM1 mutation (wtNPM1). In a multivariate Cox regression model, the quantitative FLT3ITD mRNA level showed an independent prognostic impact on overall survival (OS) and relapse-free survival (RFS) only in the NPM1+ subgroup (OS: hazard ratio, 5.9; [95% confidence interval [CI]: 3.1-11.2]; RFS: hazard ratio, 7.5 [95% CI: 3.4-16.5]). The FLT3ITD mRNA level contributes to relapse risk stratification and might help to guide postremission therapy in NPM1-mutated AML.     

C/EBPA gene mutation and C/EBPA promoter hypermethylation in acute myeloid leukemia with normal cytogenetics

In the current study, we investigated C/EBPA gene mutations and promoter hypermethylation in a series of 53 patients with CN‐AML. In addition, we also analyzed two other frequent mutations (FLT3/ITD and NPM1) in these patients and correlated them with C/EBPA gene alterations. 13/53 patients were FLT3/ITD+/NPM1‐, 11/53 patients were FLT3/ITD+/NPM1+, 9/53 patients were FLT3/ITD‐/NPM1+, and 20/53 patients were FLT3/ITD‐/NPM1‐. Four of 53 cases displayed C/EBPA mutations, whereas 49 cases had only C/EBPA wild‐type alleles. Of the four positive cases, three patients had N‐terminal mutations only, whereas one patient had mutations in both the N‐ and C‐terminal region. Two of the four positive cases also harbored both FLT3/ITD and NPM1 mutation simultaneously, whereas the other two patients had neither FLT3/ITD nor NPM1 mutations. Furthermore, 7/53 cases displayed C/EBPA promoter hypermethylation. Interestingly, they were all in CN‐AML cases without FLT3/ITD or NPM1 mutations. None of the seven patients with C/EBPA promoter hypermethylation showed C/EBPA mutation. In conclusion, C/EBPA mutation and promoter hypermethylation can be detected at a relatively low frequency in de novo CN‐AML patients, suggesting they may contribute to leukemogenesis. C/EBPA mutation appears to be seen in “high‐risk” AML (FLT3/ITD+/NPM1+; FLT3/ITD+/NPM1‐ or FLT3/ITD‐/NPM1‐), while C/EBPA hypermethylation appears to be more common in AML with FLT3/ITD‐ /NPM1‐ and is not associated with C/EBPA mutation. Am. J. Hematol. 2010. © 2010 Wiley‐Liss, Inc.     

Mutant nucleophosmin (NPM1) predicts favorable prognosis in younger adults with acute myeloid leukemia and normal cytogenetics: interaction with other gene mutations

To assess the prognostic relevance of mutations in the NPM1 gene encoding a nucleocytoplasmic shuttle protein in younger adults with acute myeloid leukemia (AML) and normal cytogenetics, sequencing of NPM1 exon 12 was performed in diagnostic samples from 300 patients entered into 2 consecutive multicenter trials of the AML Study Group (AMLSG). Treatment included intensive double-induction therapy and consolidation therapy with high cumulative doses of high-dose cytarabine. NPM1 mutations were identified in 48% of the patients including 12 novel sequence variants, all leading to a frameshift in the C-terminus of the nucleophosmin 1 (NPM1) protein. Mutant NPM1 was associated with specific clinical, phenotypical, and genetic features. Statistical analysis revealed a significant interaction of NPM1 and FLT3 internal tandem duplications (ITDs). NPM1 mutations predicted for better response to induction therapy and for favorable overall survival (OS) only in the absence of FLT3 ITD. Multivariable analysis for OS revealed combined NPM1-mutated/FLT3 ITD-negative status, CEBPA mutation status, availability of a human leukocyte antigen (HLA)-compatible donor, secondary AML, and lactate dehydrogenase (LDH) as prognostic factors. In conclusion, NPM1 mutations in the absence of FLT3 ITD define a distinct molecular and prognostic subclass of young-adult AML patients with normal cytogenetics.     

Prognostic implications of NPM1 mutations and FLT3 internal tandem duplications in Egyptian patients with cytogenetically normal acute myeloid leukemia

Nucleophosmin (NPM1) and fms-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) gene mutations represent the most frequent molecular aberrations in patients with cytogenetically normal-acute myeloid leukemia (CN-AML). We analyzed the prognostic impact of these mutations and their interactions in adults with CN-AML. NPM1 mutation (NPM1mut) and FLT3-ITD mutation (FLT3-ITD+) were analyzed by polymerase chain reaction and GeneScan assays of bone marrow samples obtained from newly diagnosed 104 CN-AML patients. FLT3-ITD+ and NPM1mut were detected in 36 (34.6%) and 30 (28.8%) out of 104 subjects, respectively, 16 cases (15.4%) had double NPM1mut/FLT3-ITD+. The incidence of FLT3-ITD+ was significantly higher in the NPM1mut group than in the NPM1 wild (NPM1wt) group (P = 0.018). Statistical analysis revealed that isolated NPM1mut group had a better clinical outcomes in terms of higher complete response (CR) rate (P = 0.01) and a trend towards favorable overall survival (OS) and disease-free survival (DFS) (P = 0.28, 0.40, respectively). In contrast, the isolated FLT3-ITD+ group had an unfavorable outcome in terms of lower CR rate (P = 0.12), shorter OS, and DFS (P < 0.0001 for both). The NPM1mut/FLT3-ITD-group had the best OS and DFS, while the NPM1wt/FLT3-ITD+ group had the worst OS and DFS than other groups (NPM1mut/FLT3-ITD+ or NPM1wt/FLT3-ITD?) (P < 0.0001 for both). Multivariate Cox regression analysis showed that age and FLT3/ITD+ were independent poor prognostic factors for OS (P = 0.006, <0.0001, respectively), while FLT3/ITD+ was independent predictor for DFS (P = 0.04). However, NPM1mut did not have a significant impact on OS and DFS. In conclusion, adult patients with CN-AML carrying isolated NPM1mut and isolated FLT3-ITD+ exhibit different clinical outcomes than those with NPM1mut/FLT3-ITD+ or NPM1wt/FLT3-ITD?. Patients with NPM1mut/FLT3-ITD? had the best prognosis in terms of higher CR, OS, and DFS, while those with NPM1mut/FLT3-ITD+ had the worst CR rate, and NPM1wt/FLT3-ITD+ had the lowest OS and DFS.     

Identification of emerging FLT3 ITD‐positive clones during clinical remission and kinetics of disease relapse in acute myeloid leukaemia with mutated nucleophosmin

FLT3 internal tandem duplication (ITD) mutations are frequently detected at diagnosis in cytogenetically normal acute myeloid leukaemia (CN‐AML) and predict unfavourable outcome. FLT3 ITD is an unstable aberration and may be lost or acquired at relapse. Recent whole genome sequencing studies have suggested that FLT3 ITD⁺ve AML relapse may evolve from small subclones undetectable at diagnosis by routine polymerase chain reaction (PCR). We developed a patient‐specific real‐time quantitative‐PCR (RQ‐PCR) to implement FLT3 ITD detection in six AML patients whose blasts carried wild‐type FLT3 at diagnosis and who relapsed with FLT3 ITD by routine PCR. Patient‐specific forward primers were designed after cloning and sequencing the FLT3 ITD in each case. The assay allowed retrospective detection of FLT3 ITD in diagnostic samples of 4/6 cases and to establish the kinetics of clonal evolution preceding relapse. After conventional chemotherapy, all patients had early relapse despite having been classified as NPM1⁺ve/FLT3 ITD^?ve at presentation, with shorter remissions being observed in four patients re‐classified as FLT3 ITD⁺ve by the new assay. Notably, FLT3 ITD clone became detectable by conventional PCR in three patients tested during remission after initial treatment. Our data underscore the need of identifying low FLT3 ITD levels, which are probably associated with relapse in otherwise good prognosis CN‐AML.     

The impact of FLT3 internal tandem duplication mutant level, number, size, and interaction with NPM1 mutations in a large cohort of young adult patients with acute myeloid leukemia

An internal tandem duplication in the fms-like tyrosine kinase 3 gene (FLT3/ITD) is associated with poor prognosis in acute myeloid leukemia (AML), but the impact of mutant level, size, and interaction with nucleophosmin 1 (NPM1) mutations remains controversial. We evaluated these characteristics in a large cohort of young adult AML patients. There was a highly significant trend for worsening in relapse risk (RR) and overall survival (OS) with increasing FLT3/ITD mutant level (P < .001 for both), and even in the low level mutant group (1%-24% of total FLT3 alleles), RR was significantly worse than in the FLT3 wild-type (WT) group (P < .001). In multivariate analysis, mutant level was the most powerful prognostic factor for RR. Mutant size and number had no significant impact on outcome. The beneficial impact of an NPM1 mutation on RR and OS was seen in FLT3/ITD(+) as well as FLT3/WT patients; both markers were highly significant independent predictors of outcome (P < .001). Stratification using both markers identified 3 prognostic groups: good (FLT3/ITD(-)NPM1(+)), intermediate (FLT3/ITD(-)NPM1(-) or FLT3/ITD(+)NPM1(+)), and poor (FLT3/ITD(+)NPM1(-)). Patients with high FLT3/ITD mutant level (greater than 50%) or FLT3/ITD(+) in the absence of an NPM1 mutation may be good candidates for more experimental therapeutic approaches.     

Acute myeloid leukaemia (AML) with t(6;9)(p23;q34) is associated with poor outcome in childhood AML regardless of FLT3‐ITD status: a report from the Children's Oncology Group

Acute myeloid leukaemia (AML) with t(6;9)(p23;q34) is a rare subtype associated with FLT3‐internal tandem duplication (ITD) and poor outcomes. The clinical outcomes of paediatric patients with t(6;9) with and without FLT3‐ITD treated on six consecutive cooperative trails were evaluated. In contrast to patients without t(6;9), those with t(6;9) had a significantly lower complete remission rate, higher relapse rate (RR), and poor overall survival (OS). Within t(6;9) patients, those with and without FLT3‐ITD had an OS of 40% and 27% respectively (P > 0·9), demonstrating that t(6;9) is a high‐risk cytogenetic feature in paediatric AML and its clinical impact is independent of the presence of FLT3‐ITD.     

Salvage therapy using FLT3 inhibitors may improve long‐term outcome of relapsed or refractory AML in patients with FLT3‐ITD

To determine the long‐term efficacy of FLT3 inhibitors (FLT3i) in the salvage setting for relapsed and refractory (rel/ref) acute myeloid leukemia (AML) with FLT3 internal tandem duplication (AML FLT3‐ITD), we conducted a retrospective study of 120 patients with rel/ref AML FLT3‐ITD who received salvage therapy with either FLT3i‐containing regimen (FLT3i group, N = 45) or conventional cytotoxic regimen (conventional group, N = 75). The median overall survival (OS) after the first salvage in the FLT3i group was 6·9 vs. 4·6 months in the conventional group (P = 0·17). The OS was better in the FLT3i group among patients with initial complete remission (CR) duration ≤12 months or with primary refractory disease (6·9 vs. 3·7 months; P < 0·01). The OS was better when FLT3i was combined with cytotoxic agents versus monotherapy (17 vs. 4·8 months; P = 0·017). Multivariate analysis revealed that the use of FLT3i was an independent predictor of OS (hazard ratio 0·58; 95% confidence interval, 0·38–0·88). Incorporating FLT3i into salvage strategies may improve long‐term outcome of patients with AML FLT3‐ITD. Prospective studies to validate this conclusion are warranted.     

Sorafenib plus all‐trans retinoic acid for AML patients with FLT3‐ITD and NPM1 mutations

Knowledge of the molecular basis of acute myeloid leukaemia has increased considerably in the past few years, and therapies targeting specific molecular defects of this disease are intensively investigated. Patients with both NPM1 and FLT3‐ITD mutations encompass 20% of cytogenetically normal AML. The multikinase and FLT3 inhibitor, sorafenib, has shown some efficacy in patients with relapsed FLT3‐ITD⁺ AML. In addition, it is suggested that all‐trans retinoic acid (ATRA) used in combination with chemotherapy has shown to improve outcome of patients harbouring NPM1 mutations. We report here the clinical course of three patients with refractory or relapsed FLT3‐ITD⁺/NPM1⁺ AML who achieved significant response upon sorafenib and ATRA combination.     

Haematopoietic cell transplantation with and without sorafenib maintenance for patients with FLT3‐ITD acute myeloid leukaemia in first complete remission

We performed a retrospective study analysing the effect of sorafenib, an oral fms‐Like Tyrosine Kinase 3 (FLT3)/multikinase inhibitor, as post‐transplant maintenance in adult patients with FLT3‐internal tandem duplication (ITD) acute myeloid leukaemia (AML). We identified consecutive patients with FLT3‐ITD AML diagnosed between 2008 and 2014 who received haematopoietic cell transplantation (HCT) in first complete remission (CR1). Post‐HCT initiation of sorafenib (yes/no) was evaluated as a time‐varying covariate in the overall survival/progression‐free survival (OS/PFS) analysis and we performed a landmark analysis of controls alive without relapse at the median date of sorafenib initiation. We identified 26 sorafenib patients and 55 controls. Median follow‐up was 27·2 months post‐HCT for sorafenib survivors, and 38·4 months for controls (P = 0·021). The median time to initiating sorafenib was 68 days post‐HCT; 43 controls were alive without relapse at this cut‐off. Sorafenib patients had improved 2‐year OS in the d+68 landmark analysis (81% vs. 62%, P = 0·029). Sorafenib was associated with improved 2‐year PFS (82% vs. 53%, P = 0·0081) and lower 2‐year cumulative incidence of relapse (8·2% vs. 37·7%, P = 0·0077). In multivariate analysis, sorafenib significantly improved OS [Hazard ratio (HR) 0·26, P = 0·021] and PFS (HR 0·25, P = 0·016). There was no difference in 2‐year non‐relapse mortality (9·8% vs. 9·3%, P = 0·82) or 1‐year chronic graft‐versus‐host disease (55·5% vs. 37·2%, P = 0·28). These findings suggest potential benefit of post‐HCT sorafenib in FLT3‐ITD AML, and support further evaluation of post‐HCT FLT3 inhibition.     

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. Am. J. Hematol. 90:904–909, 2015. © 2015 Wiley Periodicals, Inc.     

Prognostic significance ofFLT3 internal tandem duplication andNPM1 mutations in acute myeloid leukemia in an unselected patient population

Mutations in the fms-like tyrosine kinase 3 (FLT3) gene containing an internal tandem duplication (FLT3/ITD) or mutations in the nucleophosmin 1 gene (NPM1) are thought to be prognostic indicators in acute myeloid leukemia (AML). Previous studies suggested that FLT3/ITD mutation indicates a poor prognosis and that NPM1 mutation indicates a more favorable one, but these studies were often performed with selected patient populations. We investigated the clinical significance of these mutations at our institution with an unselected group of patients with newly diagnosed AML. This group included patients > or =60 years old and those with a poor performance status. Using polymerase chain reaction and sequencing analyses, we detected FLT3/ITD mutations in 12 patients (20.0%) and NPM1 mutations in 7 patients (11.7%) among a group of 60 patients. There was a nonsignificant trend for FLT3/ITD mutation to be associated with a poorer predicted overall survival (OS) probability in this population. In contrast, OS was significantly higher in patients with wild-type NPM1 than in patients with NPM1 mutation, both for all AML patients and for AML patients with a normal karyotype. In this general and unselected AML patient population, NPM1 mutation was not a prognostic indicator of a favorable outcome.     

Persistent MRD before and after allogeneic BMT predicts relapse in children with acute lymphoblastic leukaemia

Minimal residual disease (MRD) during early chemotherapy is a powerful predictor of relapse in acute lymphoblastic leukaemia (ALL) and is used in children to determine eligibility for allogeneic haematopoietic stem cell transplantation (HSCT) in first (CR1) or later complete remission (CR2/CR3). Variables affecting HSCT outcome were analysed in 81 children from the ANZCHOG ALL8 trial. The major cause of treatment failure was relapse, with a cumulative incidence of relapse at 5 years (CIR) of 32% and treatment‐related mortality of 8%. Leukaemia‐free survival (LFS) and overall survival (OS) were similar for HSCT in CR1 (LFS 62%, OS 83%, n = 41) or CR2/CR3 (LFS 60%, OS 72%, n = 40). Patients achieving bone marrow MRD negativity pre‐HSCT had better outcomes (LFS 83%, OS 92%) than those with persistent MRD pre‐HSCT (LFS 41%, OS 64%, P < 0·0001) or post‐HSCT (LFS 35%, OS 55%, P < 0·0001). Patients with B‐other ALL had more relapses (CIR 50%, LFS 41%) than T‐ALL and the main precursor‐B subtypes including BCR‐ABL1, KMT2A (MLL), ETV6‐RUNX1 (TEL‐AML1) and hyperdiploidy >50. A Cox multivariate regression model for LFS retained both B‐other ALL subtype (hazard ratio 4·1, P = 0·0062) and MRD persistence post‐HSCT (hazard ratio 3·9, P = 0·0070) as independent adverse prognostic variables. Persistent MRD could be used to direct post‐HSCT therapy.     

Long term impact of hyperleukocytosis in newly diagnosed acute myeloid leukemia patients undergoing allogeneic stem cell transplantation: An analysis from the acute leukemia working party of the EBMT

Up to 20% of acute myeloid leukemia (AML) patients present initially with hyperleukocytosis, placing them at increased risk for early mortality during induction. Yet, it is unknown whether hyperleukocytosis still retains prognostic value for AML patients undergoing hematopoietic stem cell transplantation (HSCT). Furthermore, it is unknown whether hyperleukocytosis holds prognostic significance when modern molecular markers such as FLT3‐ITD and NPM1 are accounted for. To determine whether hyperleukocytosis is an independent prognostic factor influencing outcome in transplanted AML patients we performed a retrospective analysis using the registry of the acute leukemia working party of the European Society of Blood and Marrow Transplantation. A cohort of 357 patients with hyperleukocytosis (159 patients with white blood count [WBC] 50 K‐100 K, 198 patients with WBC ≥ 100 K) was compared to 918 patients without hyperleukocytosis. Patients with hyperleukocytosis were younger, had an increased rate of favorable risk cytogenetics, and more likely to be FLT3 and NPM1 mutated. In multivariate analysis, hyperleukocytosis was independently associated with increased relapse incidence (hazard ratio [HR] of 1.55, 95% confidence interval [CI], 1.14‐2.12; P = .004), decreased leukemia‐free survival (HR of 1.38, 95% CI, 1.07‐1.78; P = .013), and inferior overall survival (HR of 1.4, 95% CI, 1.07‐1.84; P = .013). Hyperleukocytosis retains a significant prognostic role for AML patients undergoing HSCT.     

Maintenance lenalidomide in combination with 5‐azacitidine as post‐remission therapy for acute myeloid leukaemia

In this Phase 1b study, the safety and tolerability of maintenance therapy, comprising lenalidomide (0–25 mg, days 5–25) in combination with azacitidine (50–75 mg/m², days 1–5) every 28 d, was explored in 40 patients with acute myeloid leukaemia (AML) in complete remission after chemotherapy. Eligibility included AML in first complete remission (CR1) with adverse risk karyotype (n = 8), fms‐related tyrosine kinase 3‐internal tandem duplication (FLT3‐ITD) (n = 5), age ≥60 years (n = 31) or AML in second remission (CR2) (n = 14). Dose‐limiting toxicity was not reached. Common toxicities were haematological, infection, injection pain, constipation, fatigue and diarrhoea. In CR1, median relapse‐free (RFS) and overall survival (OS) was 12 and 20 months, respectively. In CR2, median RFS was 11 months, with median OS not yet reached. Among 29 patients with intermediate cytogenetic risk, RFS was 50% at 24 months. There were five patients with concomitant FLT3‐ITD and nucleophosmin (NPM1) mutation; none have relapsed and all are still alive after 17–39 months. Maintenance lenalidomide/azacitidine augmented the function of cytotoxic T lymphocytes, particularly in patients with NPM1 mutation. The lenalidomide/azacitidine maintenance combination was effective in suppressing residual DNA (cytosine‐5‐)‐methyltransferase 3 alpha (DNMT3A)‐positive disease, resulting in sustained remission in patients with concurrent NPM1 mutation. Azacitidine/lenalidomide as maintenance therapy for high‐risk AML warrants further exploration.     

Clofarabine-containing conditioning regimen for allo-SCT in AML/ALL patients: a survey from the Acute Leukemia Working Party of EBMT

Clofarabine (CLO), a second‐generation purine analogue, has demonstrated an efficient anti‐leukemia activity while showing a favorable toxicity profile. This retrospective multicenter report assessed the outcome of 90 patients who received a CLO‐containing conditioning regimen before allo‐SCT for AML (n = 69) or ALL (n = 21). Median age was 42 yr at transplant. The majority of cases (n = 66) presented with an active disease at transplant while 38 patients had received previous transplantation(s). A total of 88 and two patients received a reduced‐intensity conditioning or a myeloablative regimen, respectively. Engraftment was achieved in 97% of evaluable patients. With a median follow‐up of 14 months (range, 1–45), the 2‐year OS, LFS, relapse, and NRM rates were 28 ± 5%, 23 ± 5%, 41 ± 6%, and 35 ± 5%, respectively. When comparing AML and ALL patients, OS and LFS were significantly higher for AML (OS, 35 ± 6% vs. 0%, P < 0.0001); LFS: 30 ± 6% vs. 0%, P < 0.0001). In a Cox multivariate analysis, an AML diagnosis was the only factor associated with a better LFS ( HR = 0.37; 95%CI, 0.21–0.66; P = 0.001). We conclude that a CLO‐containing conditioning regimen prior to allo‐SCT might be an effective treatment. Prospective studies are needed to evaluate the potential role of CLO as part of conditioning regimens in acute leukemias.     

Treatment of children with acute myeloid leukaemia who relapsed after allogeneic haematopoietic stem cell transplantation

Despite improvements in diagnosis and treatment, 30–40% of children with acute myeloid leukaemia (AML) experience relapse. For those who relapse after allogeneic haematopoietic stem cell transplantation (allo‐HSCT), the prognosis is particularly poor, with limited reported literature on these patients. We reviewed the clinical course of 49 children with AML (28 males, 21 females) who received allo‐HSCT between 1993 and 2011, and who had subsequently relapsed. Study endpoints included (i) complete remission (CR) rate after intensive chemotherapy, and prognostic factors for CR, (ii) disease‐free survival (DFS) and overall survival (OS) for patients who achieved CR and (iii) OS for recipients of intensive chemotherapy and prognostic factors for OS . Of the 36 patients who received intensive chemotherapy after post‐HSCT relapse, 26 (72%) achieved CR. For patients who achieved CR, 5‐year DFS and OS were 32·6 ± 10·2% and 44·4 ± 11·1%, respectively. For all recipients of intensive chemotherapy, 5‐year OS was 31·6 ± 8·7%. Cumulative incidence of treatment‐related death was 14·4%. All three recipients of second HSCT died. Amongst prognostic factors predicting improved survival, only disease status at HSCT (early first CR vs. others) proved significant in multivariate study (Hazard Ratio 2·42, 95% Confidence Interval 1·02–5·74, P = 0·045). Treatment with curative intent was able to salvage a minor but important subset of children with AML who relapsed post‐allogeneic transplant.