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

Monocytic Differentiation of Human Acute Myeloid Leukemia Cells: A Proteomic and Phosphoproteomic Comparison of FAB-M4/M5 Patients with and without Nucleophosmin 1 Mutations

Even though morphological signs of differentiation have a minimal impact on survival after intensive cytotoxic therapy for acute myeloid leukemia (AML), monocytic AML cell differentiation (i.e., classified as French/American/British (FAB) subtypes M4/M5) is associated with a different responsiveness both to Bcl-2 inhibition (decreased responsiveness) and possibly also bromodomain inhibition (increased responsiveness). FAB-M4/M5 patients are heterogeneous with regard to genetic abnormalities, even though monocytic differentiation is common for patients with Nucleophosmin 1 (NPM1) insertions/mutations; to further study the heterogeneity of FAB-M4/M5 patients we did a proteomic and phosphoproteomic comparison of FAB-M4/M5 patients with (n = 13) and without (n = 12) NPM1 mutations. The proteomic profile of NPM1-mutated FAB-M4/M5 patients was characterized by increased levels of proteins involved in the regulation of endocytosis/vesicle trafficking/organellar communication. In contrast, AML cells without NPM1 mutations were characterized by increased levels of several proteins involved in the regulation of cytoplasmic translation, including a large number of ribosomal proteins. The phosphoproteomic differences between the two groups were less extensive but reflected similar differences. To conclude, even though FAB classification/monocytic differentiation are associated with differences in responsiveness to new targeted therapies (e.g., Bcl-2 inhibition), our results shows that FAB-M4/M5 patients are heterogeneous with regard to important biological characteristics of the leukemic cells.

Pediatric acute myeloid leukemia and hyperleukocytosis with WBC count greater than 50 × 109/L

BACKGROUND

Acute myeloid leukemia (AML) and hyperleukocytosis have an unfavorable prognosis, but the impact of hyperleukocytosis on the prognosis of pediatric AML remains uncertain. We investigated the clinical characteristics and prognosis of pediatric AML with hyperleukocytosis, defined as WBC ≥ 50 × 109/L.

METHODS

A total of 132 patients with newly diagnosed childhood AML with hyperleukocytosis were consecutively enrolled at our center from September 2009 to August 2021 to investigate prognostic factors and clinical outcomes.

RESULTS

Hyperleukocytosis occurred in 27.4% of AML patients. Pediatric patients with hyperleukocytosis had similar CR and OS rates to those without hyperleukocytosis, but had a lower EFS rate. In our study, rates of CR1, mortality, relapsed/refractory disease, and HSCT were comparable between AML patients with WBC counts of 50-100 × 109/L and ≥ 100 × 109/L. AML patients with a WBC count of 50-100 × 109/L had a similar 5-year OS rate to patients with a WBC count ≥ 100 × 109/L (74.6% vs. 75.4%, P = 0.921). Among all patients with hyperleukocytosis, the FAB M5 subtype was associated with significantly inferior survival, and the prognosis of CBF-AML was good.

CONCLUSIONS

Pediatric AML patients with hyperleukocytosis have the similar prognosis regardless of whether their WBC count is 50-100 × 109/L or ≥ 100 × 109/L.

Influence on therapeutic outcome of platelet count at diagnosis in patients with de novo non-APL acute myeloid leukemia

BACKGROUND

Platelet (PLT) count at diagnosis plays an important role in cancer development and progression in solid tumors. However, it remains controversial whether PLT count at diagnosis influences therapeutic outcome in patients with non-acute promyelocytic leukemia (APL) acute myeloid leukemia (AML).

METHODS

This study analyzed the relationship between PLT count at diagnosis and genetic mutations in a cohort of 330 newly diagnosed non-APL AML patients. The impact of PLT count on complete remission, minimal residual disease status and relapse-free survival (RFS) were evaluated after chemotherapy or allogeneic hematopoietic stem cell transplantation (allo-HSCT).

RESULTS

Our studies showed that patients with DNMT3A mutations have a higher PLT count at diagnosis, while patients with CEBPA biallelic mutations or t(8;21)(q22; q22) translocation had lower PLT count at diagnosis. Furthermore, non-APL AML patients with high platelet count (> 65 × 109/L) at diagnosis had worse response to induction chemotherapy and RFS than those with low PLT count. In addition, allo-HSCT could not absolutely attenuated the negative impact of high PLT count on the survival of non-APL AML patients.

CONCLUSION

PLT count at diagnosis has a predictive value for therapeutic outcome for non-APL AML patients.

Modern Risk Stratification of Acute Myeloid Leukemia in 2023: Integrating Established and Emerging Prognostic Factors

An accurate estimation of AML prognosis is complex since it depends on patient-related factors, AML manifestations at diagnosis, and disease genetics. Furthermore, the depth of response, evaluated using the level of MRD, has been established as a strong prognostic factor in several AML subgroups. In recent years, this rapidly evolving field has made the prognostic evaluation of AML more challenging. Traditional prognostic factors, established in cohorts of patients treated with standard intensive chemotherapy, are becoming less accurate as new effective therapies are emerging. The widespread availability of next-generation sequencing platforms has improved our knowledge of AML biology and, consequently, the recent ELN 2022 recommendations significantly expanded the role of new gene mutations. However, the impact of rare co-mutational patterns remains to be fully disclosed, and large international consortia such as the HARMONY project will hopefully be instrumental to this aim. Moreover, accumulating evidence suggests that clonal architecture plays a significant prognostic role. The integration of clinical, cytogenetic, and molecular factors is essential, but hierarchical methods are reaching their limit. Thus, innovative approaches are being extensively explored, including those based on "knowledge banks". Indeed, more robust prognostic estimations can be obtained by matching each patient's genomic and clinical data with the ones derived from very large cohorts, but further improvements are needed.

A novel risk model for predicting early relapse in acute myeloid leukemia patients undergoing allogeneic hematopoietic stem-cell transplantation

Relapse remains the leading cause of death in acute myeloid leukemia (AML) patients following allogeneic hematopoietic stem-cell transplantation (allo-HSCT), limiting the efficacy of allo-HSCT. Thus, the ability to identify high-risk patients in a manner that permits early intervention has the potential to improve survival outcomes. We retrospectively enrolled 414 younger patients (aged 14-60 years) with AML who received allo-HSCT between January 2014 and May 2020. From June 2020 to June 2021, 110 consecutive patients were included prospectively in the validation cohort. The primary outcome was early relapse (relapse within 1 year). The cumulative incidence of early relapse after allo-HSCT was 11.8%. The overall survival rate for patients who relapsed within 1-year was 4.1% at 3 years after relapse. After multivariable adjustment, statistically significant associations between primary resistance, pre-transplantation measurable residual disease, DNMT3A mutation, or white blood cell count at diagnosis and early relapse were observed. An early relapse prediction model was developed based on these factors and the model performed well. Patients deemed to have a high risk or a low risk of early relapse had early relapse rates of 26.2% and 6.8%, respectively (P < 0.001). The prediction model could be used to help identify patients at risk for early relapse and to guide personalized relapse prevention.

Clinical characteristics and outcomes of children with newly diagnosed acute myeloid leukemia and hyperleukocytosis managed with different cytoreductive methods

BACKGROUND

Hyperleukocytosis in patients with acute myeloid leukemia (AML) has been associated with worse outcomes. For cytoreduction, leukapheresis has been used but its clinical utility is unknown, and low-dose cytarabine (LD-cytarabine) is used as an alternative method.

METHODS

Children with newly diagnosed AML treated between 1997 and 2017 in institutional protocols were studied. Hyperleukocytosis was defined as a leukocyte count of ≥100 × 109 /L at diagnosis. Clinical characteristics, early complications, survival data, and effects of cytoreductive methods were reviewed. Among 324 children with newly diagnosed AML, 49 (15.1%) presented with hyperleukocytosis. Initial management of hyperleukocytosis included leukapheresis or exchange transfusion (n = 16, considered as one group), LD-cytarabine (n = 18), hydroxyurea (n = 1), and no leukoreduction (n = 14).

RESULTS

Compared with patients who received leukapheresis, the percentage decrease in leukocyte counts following intervention was greater among those who received LD-cytarabine (48% vs. 75%; p = .02), with longer median time from diagnosis to initiation of protocol therapy (28.1 vs. 95.2 hours; p < .001). The incidence of infection was higher in patients (38%) who had leukapheresis than those who receive LD-cytarabine (0%) or leukoreduction with protocol therapy (14%) (p = .008). No differences were noted in the outcomes among the intervention groups. Although patients with hyperleukocytosis had higher incidences of pulmonary and metabolic complications than did those without, no early deaths occurred, and the complete remission, event-free survival, overall survival rates, and outcomes of both groups were similar.

CONCLUSION

LD-cytarabine treatment appears to be a safe and effective means of cytoreduction for children with AML and hyperleukocytosis.

Characteristics and Outcomes of Secondary Acute Myeloid Leukemia and Acute Myeloid Leukemia With Myelodysplasia-Related Changes: Multicenter Study From the Thai Acute Leukemia Study Group

BACKGROUND

Secondary acute myeloid leukemia (sAML) and AML with myelodysplasia-related changes (AML-MRC) both result in dismal outcomes. This retrospective study aimed to determine whether these features are poor prognostic factors independent of older age and adverse cytogenetics, which are commonly associated with a poor prognosis.

METHODS

The characteristics and real-world outcomes of sAML and AML-MRC from the Thai AML registry database were investigated.

RESULTS

From a total of 992 newly diagnosed AML patients, 315 (31.8%) patients were classified into sAML or AML-MRC subtypes. Older age, low white blood cell (WBC) count, low bone marrow blast, and adverse cytogenetic risk were commonly present in sAML and AML-MRC compared to de novo AML. Complete remission after 7 + 3 induction therapy occurred in 42.3% of patients with sAML or AML-MRC and 62.4% of de novo AML (P < .001). The median overall survival (OS) of sAML, AML-MRC, and de novo AML were 6.9, 7.0, and 12.2 months, respectively (P < .001). The independent prognostic factors for inferior OS were older age, intermediate-risk or adverse-risk cytogenetics, WBC count > 100 × 10⁹/L, poor performance status, and a subgroup of AML-MRC with the morphologic criteria of multilineage dysplasia (AML-MRC-M). In addition, sAML, AML-MRC, and a WBC count > 100 × 10⁹/L were pre-treatment prognostic factors associated with poor relapse-free survival (P = .006, P = .017, and P < .001, respectively).

CONCLUSION

Both sAML and AML-MRC are independently associated with poor outcomes in Thai patients. Our study supports AML-MRC-M as an adverse prognostic factor for OS.

How we use molecular minimal residual disease (MRD) testing in acute myeloid leukaemia (AML)

In recent years there have been major advances in the use of molecular diagnostic and monitoring techniques for patients with acute myeloid leukaemia (AML). Coupled with the simultaneous explosion of new therapeutic agents, this has sown the seeds for significant improvements to treatment algorithms. Here we show, using a selection of real-life examples, how molecular monitoring can be used to refine clinical decision-making and to personalise treatment in patients with AML with nucleophosmin (NPM1) mutations, core binding factor translocations and other fusion genes. For each case we review the established evidence base and provide practical recommendations where evidence is lacking or conflicting. Finally, we review important technical considerations that clinicians should be aware of in order to safely exploit these technologies as they undergo widespread implementation.

Hyperleukocytosis predicts inferior clinical outcome in pediatric acute myeloid leukemia

OBJECTIVES

Hyperleukocytosis (HL) is a laboratory abnormality commonly presented in patients with acute myeloid leukemia (AML). However, large cohort studies on the clinical significance of HL in pediatric AML are paucity. Moreover, the effect of stem cell transplantation in HL patients remains unknown.

METHODS

The clinical profiles of 885 pediatric patients with AML were downloaded from the TARGET dataset. HL was defined as an initial peripheral WBC count of ≥ 100 ×10⁹/L. We analyzed the prevalence, clinical profile and prognosis of HL in these patients.

RESULTS

The frequency of HL among all the pediatric AML was 22.6%. FMS-like tyrosine kinase 3/internal tandem duplication (FLT3/ITD) mutation and gene fusion of NUP98/NSD1 occurred with higher incidence in HL patients. Overall, HL was associated with a low induction complete remission rate, and high risk of induction death. Moreover, HL predicted a significantly inferior 5-year event-free survival (EFS) (P < 0.001) and a trend of inferior 5-year overall survival (OS) (P = 0.059). However, compared with chemotherapy, stem cell transplantation had no significant effect on the survival of HL patients in terms of 5-year leukemia-free survival (P = 0.449) or OS (P = 0.447). Multivariate analysis revealed that HL was an independent prognosis factor for EFS (Hazard ratio:1.352, P = 0.013) but not for OS (Hazard ratio:1.225, P = 0.170) in pediatric AML.

CONCLUSION

HL might predict inferior clinical outcome in pediatric AML. SCT is an effective therapy for AML, but it may have no better effect on the survival of patients with HL, compared to chemotherapy.

New agents in acute myeloid leukemia (AML)

Despite expanding knowledge in the molecular landscape of acute myeloid leukemia (AML) and an increasing understanding of leukemogenic pathways, little has changed in the treatment of AML in the last 40 years. Since introduction in the 1970s, combination chemotherapy consisting of anthracycline and cytarabine has been the mainstay of treatment, with major therapeutic advances based on improving supportive care rather than the introduction of novel therapeutics. Over the last decades, there have been extensive efforts to identify specific target mutations or pathways with the aim of improving clinical outcomes. Finally, after a prolonged wait, we are witnessing the next wave of AML treatment, characterized by a more “precise” and “personalized” understanding of the unique molecular or genetic mapping of individual patients. This new trend has since been further facilitated, with four new FDA approvals granted in 2017 in AML therapeutics. Currently, a total of eight targeted agents have been approved since 2017 (as of Jan. 2020). In this review, we will briefly discuss these newer agents in the context of their indication and the basis of their approval.

Impact Of ELN Risk Stratification, Induction Chemotherapy Regimens And Hematopoietic Stem Cell Transplantation On Outcomes In Hyperleukocytic Acute Myeloid Leukemia With Initial White Blood Cell Count More Than 100 × 109/L

Background

Hyperleukocytic acute myeloid leukemia (AML) (initial white blood cell count≥100 × 10⁹/L) is a clinical emergency often accompanied by leukostasis syndrome, tumor lysis syndrome (TLS), and disseminated intravascular coagulation (DIC), with a poor clinical prognosis. The aim of this study retrospectively analyzed the clinical features of hyperleukocytic AML, focusing on high-risk factors affecting prognosis, the selection of initial induction therapy, and the impact of hematopoietic stem cell transplantation (HSCT) on prognosis.

Patients and methods

A total of 558 AML patients at our center from January 2013 to December 2017 were diagnosed, and 52 (9.32%) patients presented with hyperleukocytosis were retrospectively reviewed.

Results

The 3-year overall survival (OS) rate in the 15–39 years old and 40–60 years old group was 58.8% and 25.4%, respectively; the longest survival time in patients aged >60 years was only 8 months, and the 8-month OS rate was 8.3% (p=0.002). The 3-year OS rate of the patients in the favorable risk group, intermediate risk group and high risk group, according to the 2017 ELN risk stratification, was 50%, 28.0%, and 29.5%, respectively (p=0.374). The 3-year OS rate of patients carrying CEBPA or NPM1 mutation and those with FLT3-ITD or MLL mutation was 37.5% and 30.0%, respectively (p=0.63). The 3-year OS rate of patients employing an induction regimen of a standard IA regimen was 58.4%, and of those employing a non-standard IA regimen was 22.2% (p=0.065). The 3-year OS rate of the transplantation patients reached 73.8%, while the 9-month OS rate of patients without transplantation was 11.4% (p<0.001).

Conclusion

This study suggest that hyperleukocytosis is an independent risk factor for AML patients, regardless of the risk stratification based on cytogenetic or molecular abnormalities. Age is the main factor influencing the prognosis of hyperleukocytic AML. The use of a standard IA regimen and HSCT can significantly improve the patient’s prognosis.

The combination of NPM1, DNMT3A, and IDH1/2 mutations leads to inferior overall survival in AML

Acute myeloid leukemia (AML) is a genetically heterogeneous disease with a clinical course predicted by recurrent cytogenetic abnormalities and/or gene mutations. The NPM1 insertion mutations define the largest distinct genetic subset, ∼30% of AML, and is considered a favorable risk marker if there is no (or low allelic ratio) FLT3 internal tandem duplication (FLT3 ITD) mutation. However, ∼40% of patients with mutated NPM1 without FLT3 ITD still relapse, and the factors that drive relapse are still not fully understood. We used a next-generation sequencing panel to examine mutations at diagnosis; clearance of mutations after therapy, and gain/loss of mutations at relapse to prioritize mutations that contribute to relapse. Triple mutation of NPM1, DNMT3A and IDH1/2 showed a trend towards inferior overall survival in our discovery dataset, and was significantly associated with reduced OS in a large independent validation cohort. Analysis of relative variant allele frequencies suggests that early mutation and expansion of DNMT3A and IDH1/2 prior to acquisition of NPM1 mutation leads to increased risk of relapse. This subset of patients may benefit from allogeneic stem cell transplant or clinical trials with IDH inhibitors.

Acute myeloid leukemia patient with FLT3-ITD and NPM1 double mutation should undergo allogeneic hematopoietic stem cell transplantation in CR1 for better prognosis

Background: According to the recent National Comprehensive Cancer Network (NCCN) guidelines, the risk level in acute myeloid leukemia (AML) patients with FLT3-ITD and NPM1 double mutation (AML ^{FLT3-ITD+/NPM1+} ) depends on the allelic ratio of FLT3-ITD. But despite a low or high allelic ratio of FLT3-ITD, AML ^{FLT3-ITD+/NPM1+} patients belong to the favorable or intermediate risk, for whom allogeneic stem cell transplantation is not obligated. However, some latest studies pointing out that NPM1 and FLT3-ITD double mutation patients showed an inferior prognosis, which have raised concern about the risk categorization and more effective treatment of AML ^{FLT3-ITD+/NPM1+} patients. Methods: A total of 76 patients were selected for coexisting FLT3 and NPM1 mutations with normal cytogenetics. The prognostic risk factors were analyzed, and treatment strategies including allogeneic stem cell transplantati1on and chemotherapy were compared. Results: In 76 AML ^{FLT3-ITD+/NPM1+} patients, 36.8% of patients had hyperleukocytosis (HL) and DNMT3A R882 mutation was the most common concomitant gene (23.7%). For 53 patients in the complete remission (CR), 22 had received allogeneic hematopoietic stem cell transplantation (allo-HSCT) on first complete remission (CR1). Patients in transplantation group had better overall survival (OS) and disease-free survival (DFS) than chemotherapy only (P=0.002 and 0.001, respectively). In multivariable Cox model analyses, HL and DNMT3A R882 mutation were independent adverse prognostic factors (all P<0.05) for AML ^{FLT3-ITD+/NPM1+} patients. Nevertheless, allo-HSCT was an independent good factor of OS and DFS (P=0.001 and 0.000; HR =0.173 and 0.138; 95% CI were 0.062-0.483 and 0.049-0.389). And allo-HSCT could moderately improve the poor prognosis of AML ^{FLT3-ITD+/NPM1+/DNMT3A R882+}. Conclusion: Although, AML ^{FLT3-ITD+/NPM1+} patients are categorized as favorable or intermediate risk levels according to recent NCCN and ELN guidelines, these patients should receive allo-HSCT in CR1 for a longer survival. AML ^{FLT3-ITD+/NPM1+} patients with DNMT3A R882 mutation had a very poor prognosis, and allo-HSCT could moderately improve their survival.

Comparing leukapheresis protocols for an AML patient with symptomatic leukostasis

BACKGROUND

Acute myeloid leukemia (AML) is a malignancy characterized by rapid clonal proliferation of myeloid precursors, which can result in hyperleukocytosis. Leukapheresis can be used to rapidly reduce the white blood cell count (WBC). However, the only FDA cleared device for WBC depletion, the COBE Spectra, will no longer be supported by the manufacturer in 2017, and there are few studies comparing different methods of leukapheresis.

CASE REPORT

A 68-year-old African American female was admitted to the hospital for relapse of her AML. Laboratory data demonstrated a WBC count of 291 600/μL and flow cytometry of the peripheral blood demonstrated 85% myeloid blasts. Leukapheresis was ordered to help treat the leukostasis.

METHODS

Three different apheresis protocols were used to achieve cytoreduction: Spectra Optia mononuclear collection (MNC) protocol, Spectra Optia granulocyte collection (PMN) protocol, and Therakos CELLEX buffy coat collection without return. Due to different inlet flow rates, the procedures were evaluated based on the number of WBCs collected and volume of blood processed (VBP).

RESULTS

The Spectra Optia PMN collected the most WBCs and collected nearly as many WBCs per VBP as the Therakos CELLEX, which had the highest value.

CONCLUSION

To our knowledge, we are reporting the first use of Therakos CELLEX and Spectra Optia PMN protocol for WBC depletion. While the Spectra Optia granulocyte protocol showed the best performance for this AML patient, further studies will be needed to compare the Spectra Optia PMN protocol to the MNC protocol for AML patients.