Chemotherapy For Acute Myeloid Leukemia Research Articles

Measurable Residual Disease Conversion Rate with Consolidation Chemotherapy in Acute Myeloid Leukemia

Background Patients with acute myeloid leukemia (AML) who achieve complete remission (CR) following induction therapy but continue to have measurable residual disease (MRD) have inferior outcomes following allogeneic hematopoietic cell transplant (alloHCT). Determining the historical rate of MRD clearance in response to standard consolidative therapy is needed as an initial step in developing a new therapeutic strategy to clear MRD prior to alloHCT. Methods A multi-institution retrospective analysis was performed on consecutively treated AML patients in morphologic CR with detectable MRD post-induction therapy who received standard chemotherapy consolidation from January 2016 to December 2021. MRD was measured by multiparametric flow cytometry (MPFC, sensitivity 0.01-0.1%), next generation sequencing (NGS, sensitivity 1-5%), real-time quantitative PCR (qPCR, sensitivity 1:100,000-0.5%), and/or fluorescence in situ hybridization (FISH)/karyotype (sensitivity 1-5%). Any detectable disease-related abnormalities were considered to be evidence of MRD for the purpose of this study. Results Eighty-three patients met inclusion criteria for this analysis, with a median age at diagnosis of 51 years (IQR 43-63). Adverse-risk disease by ELN 2017 criteria was observed in 36 patients (43%). The majority received induction therapy with "7+3" (cytarabine + idarubicin or daunorubicin, 77 patients, 93%), and most (71 patients, 86%) required only 1 line of therapy to achieve CR. At the time of CR following induction therapy, 35 patients (42%) had MRD detected by MPFC, 38 patients (46%) had MRD detected by NGS, 10 patients (12%) had MRD detected by qPCR, and 32 patients (39%) were found to have an abnormal FISH or karyotype. Twenty-eight patients had MRD detected by more than 1 method. Consolidation therapy consisted of intermediate-dose cytarabine (defined as <3 g/m2, 41 patients, 49%) or high-dose cytarabine (defined as 3 g/m2, 39 patients, 47%) in all patients, except for 3 who received daunorubicin and cytarabine (liposomal) consolidation. The number of cycles of cytarabine consolidation were 1 cycle (36 patients, 43%), 2 cycles (23 patients, 28%), 3 cycles (15 patients, 18%), and 4 cycles (9 patients, 11%), respectively. Sixteen patients received cytarabine consolidation in combination with another agent including sorafenib (1 patient), midostaurin (10 patients), gilteritinib (1 patient), enasidenib (1 patient), and gemtuzumab (3 patients). In response to consolidation therapy, 27 of the 83 patients with measurable disease converted to MRD-negative (33%) after all given cycles of consolidation cytarabine. Of the 35 patients whose AML had MRD detected by MPFC prior to consolidation, 17 converted to MRD-negative (49%). Of the 38 patients whose AML had MRD detected by NGS prior to consolidation, 6 converted to MRD-negative (16%). Of the 10 patients whose AML had MRD detected by qPCR prior to consolidation, 6 converted to MRD-negative (60%). Of the 32 patients whose AML had MRD detected by FISH or karyotype prior to consolidation, 13 converted to MRD-negative (41%). Of note, 22 patients developed progressive disease following consolidation therapy (and therefore also did not achieve MRD-negativity). Multivariable logistic regression was performed to assess potential associations with MRD conversion during consolidation chemotherapy. Older age decreased the odds of conversion of AML to MRD-negative (OR = 0.96, 95% CI 0.92-1.00, p = 0.04). Higher ELN risk category, higher dose of cytarabine, and more cycles of consolidation did not affect the likelihood of conversion of AML to MRD-negative. Fifty-five patients received alloHCT following consolidation therapy. Thirty-one of these patients had AML with MRD detected post-consolidation, of whom 14 had MRD measured by MPFC. With a median follow-up time of 437 days post-transplant (IQR 151-914), two-year progression-free survival post-transplant was 57% in AML patients with MRD detected post-consolidation compared to 71% in AML patients with no MRD (p = 0.28). Conclusions The rate of MRD eradication with standard consolidation chemotherapy in AML is suboptimal. Combined with the known poor outcomes after alloHCT in patients with AML and detectable MRD pre-transplant, this demonstrates an unmet need to develop a new therapeutic strategy for eradicating MRD after induction therapy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Venetoclax Plus Intensive Chemotherapy in AML and Advanced MDS: Assessment of Leukemia Stem Cell Eradication By High-Resolution MRD Assay

Background: For the past five decades the standard of care for fit patients with acute myeloid leukemia (AML) has been induction with the "7+3" regimen, using a combination of cytarabine (AraC) and anthracycline (daunorubicin, idarubicin) followed by consolidation high-dose AraC (HiDAC). With this approach, approximately 70% of younger (≤60 years of age) and 60% of older (>60 yrs) fit patients achieve a complete remission, with 30-50% of those patients attaining measurable residual disease (MRD) negative state by multiparameter flow cytometry (MFC). However, even patients with MRD-negative remissions relapse due to remaining chemotherapy-resistant pre-leukemic and leukemic stem cells (LSCs). Eradication of residual disease at the LSC level is therefore the ultimate goal to achieve durable remissions and cure. The combination of Venetoclax (Ven) with chemotherapy can have a synergistic effect; by reducing the apoptotic threshold, Ven can facilitate increased apoptosis induced by genotoxic agents, while at the same time chemotherapy can downregulate MCL-1 that drives Ven resistance. Ven in combination with hypomethylating agents has shown to not only eradicate AML blasts but also target and eliminate LSCs. Early phase trials combining Ven with intensive chemotherapy (IC) have shown encouraging safety and efficacy signals. However, the optimal dose and schedule of Ven that can best synergize with IC to eradicate LSCs remain unknown. Here we present a phase 1b study evaluating the safety and tolerability of Ven in combination with daunorubicin (dauno)/AraC) induction followed by HiDAC consolidation in patients with newly diagnosed AML or high-risk myelodysplastic syndrome (MDS). Objective: The primary objectives of this study are to evaluate the safety, tolerability, and to determine the maximum tolerated dose (MTD) of the combination of Ven plus dauno & AraC, as well as HiDAC IC. Secondary objectives are response per 2017 ELN and revised IWG criteria, survival, event-free survival and duration of response. A key exploratory objective is to comprehensively analyze LSC and assess rates of LSC eradication by means of MFC and single cell sequencing ("high-resolution MRD assay"). Design: This is a Phase 1b, open-label, dose-escalation study, evaluating Ven in combination with IC in previously untreated, adult patients with AML and high-risk MDS (NCT05342584). In Part 1, we are utilizing a 3+3 design to evaluate the safety and tolerability of different Ven doses in combination with IC. In Part 2, we will evaluate the safety and clinical activity in additional 12 patients at the dose determined in Part 1. To evaluate for LSC MRD, bone marrow aspirates obtained at the time of each disease evaluation will be analyzed by high-resolution MRD assays. Specifically, we will perform multicolor flow cytometry assays optimized for primary samples and able to distinguish, quantify, and sort pre-LSCs and LSCs. Furthermore, we will combine this assay with ultra-deep sequencing (1Million x) to detect very low levels of mutant cells, importantly within the LSC compartment. Eligible patients must have a new diagnosis of AML or high-risk MDS (blasts>10% AND R-IPSS>3.5%), be 18-75 yrs of age and deemed fit for intensive chemotherapy. During induction, escalating Ven doses (400 mg x8 -> 11 -> 14 days) will be combined with AraC 100mg/m2 and 2 doses of dauno (60 and 90mg/m2) in patients aged 60yrs or younger, whereas dauno 60 will be used for all patients older than 60yrs. During consolidation, the Ven dose will be escalated (200 -> 400mg) in a similar 3+3 design at a fixed 7-day duration in combination with age-adjusted high dose AraC regimen (1.5g/m2 in ≤60yrs and 1g/m2 in >60yrs, every 12hrs on days 1,3,5). Conclusion: This study will evaluate the optimal dosing of Venetoclax and daunorubicin as part of the Ven plus "7+3" induction regimen. It will also evaluate the optimal dose of Venetoclax in combination with HiDAC consolidation chemotherapy. This trial will utilize a novel highly-sensitive LSC MRD assay to test the efficacy of Venetoclax in eliminating LSCs when combined with conventional chemotherapy.

Measures of Structural Racism Predict ICU Admission Following Intensive Chemotherapy for AML

INTRODUCTION: Recent observational studies have revealed that real-world complications of intensive chemotherapy for frontline treatment of acute myeloid leukemia (AML) far exceed those reported in clinical trials. A 2017 analysis of over 40,000 AML patients found that 26% of patients who received induction chemotherapy were admitted to the intensive care unit (ICU), with increased mortality for non-white patients (Halpern, JAMA Oncology 2016). In a newly created Chicago AML registry (Abraham, Blood 2022), higher ICU admission rate was noted following induction chemotherapy for non-white patients. The current study aims to i) describe treatment complications based on race/ethnicity and ii) examine structural racism (SR) measures as risk factors for ICU admission following intensive chemotherapy in a diverse real-world patient population. METHODS: Using the Chicago AML registry, we compared ethnoracial differences in treatment complications including infections, thrombosis, renal or liver dysfunction (defined as peak creatinine >1.5 g/dL or peak bilirubin >1.2 mg/dL), respiratory failure requiring ventilatory support and hemodynamic instability needing pressor support. We then examined associations of race/ethnicity and previously published measures of census tract disadvantage, affluence, and segregation (referred to as SR measures) with ICU admission. These structural barriers were examined alongside known predictors of treatment mortality including disease characteristics and comorbidities. Additional outcomes included duration of ICU stay and mortality. RESULTS: In this cohort of 573 patients who underwent intensive induction chemotherapy for AML, 30-day complications differed based on race/ethnicity. Renal dysfunction was highest in non-Hispanic black (NHB) patients with an incidence of 27.8% with 6% initiating dialysis compared to 17.6% of non-Hispanic white (NHW) and 11.3% of Hispanic patients with 2% needing dialysis. Hepatotoxicity was highest in Hispanic patients (64%) vs. NHB (51%) and NHW (47%). Infectious complications were highest in NHB with microbiologically documented infections in 50.6% compared to 39.7% in NHW and 32.6% in Hispanic. Venous thrombosis occurred in 14.5% of NHB patients, compared to 14.7% of NHW and 13.3% Hispanic patients. In total, 141 (24.6%) patients required ICU admission during intensive induction with rates differing significantly by race and ethnicity (p = 0.014). Average length of stay in the ICU was 7.8 days for NHB patients, 6.7 days for NHW and 6.0 days for Hispanics. Due to low 30-day mortality, we were unable to detect differences between ethnoracial groups. Mechanical ventilation was utilized in 32% of NHB compared to 26% of NHW and 20% of Hispanic patients admitted to the ICU. Vasopressor were required in 31% of NHB patients vs. 27% of NHW patients. Predictors of ICU admission in our dataset included non-white race, unmarried status, living in a neighborhood with lower % of NHW residents, and WBC > 50,000/µL at diagnosis. Additional census tract variables including higher disadvantage and lower affluence conferred nonsignificant risk. Interestingly, comorbidities, ELN Score and baseline creatinine > 1.5 g/dL were not predictors of ICU admission. CONCLUSIONS: In a real-world population of AML patients, we show variation in the spectrum of treatment complications based on race/ethnicity. Moreover, with detailed individual and neighborhood socioeconomic position (SEP) data, measures of SR predicted ICU admission following induction chemotherapy. Other significant predictors include marital status - an individual measure of SEP, and hyperleukocytosis, which may indicate delay in medical presentation. High comorbidity index did not predict increased rate of ICU admission similar to prior studies (Tawfik, J Geriatr Oncol, 2016), while renal dysfunction was a non-significant predictor. Collectively our results suggest that there is a need to incorporate individual and neighborhood SR measures to identify patients at risk of clinical decline when stressed with intensive therapies. An algorithmic approach to identify 'high risk’ patients based on clinical/molecular and structural factors could prompt more detailed assessment of fitness prior to initiation of chemotherapy and directly influence leukemia outcome disparities. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Prognostic Impact of Persistent Measurable Residual Disease in Patients with Acute Myeloid Leukemia FLT3+ Treated with Intensive Chemotherapy Plus Midostaurin - a Retrospective Study of the Polish Adult Leukemia Group (PALG)

Background: Measurable residual disease (MRD) is detected during morphological remission after standard chemotherapy in acute myeloid leukemia (AML) patients (pts). It is a strong prognostic factor for relapse and shorter overall survival (OS). Immunophenotyping by multiparameter flow cytometry (MFC) is currently the most commonly used method in AML pts. There is still a lack of studies evaluating MRD in specific AML populations in the era of targeted therapies, including thyrosine kinase inhibitors. A retrospective study in adult pts with a newly diagnosed AML FLT3+ treated with intensive chemotherapy plus midostaurin has been performed to evaluate the prognostic impact of positive MRD (MRD+) on RFS and OS. Objectives: To assess the prognostic impact of MRD status during the clinical course of AML FLT3+ on RFS and OS. Patients and methods: Seventy three pts with AML FLT3 were treated in Polish hematological centers between 2018 and 2021. Bone marrow aspiration was performed after induction and consolidation treatment to assess response and MRD by MFC. MRD+ was defined as ≥ 0.1% abnormal cells within mononucleated cells by MFC with diagnostic leukemia-associated immunophenotype (LAIP) and different from normal (DfN) aberrant immunophenotype approaches. Results: The median age of the pts was 55 (range: 18-74). Induction regimen was DA "3+7" in 50 (70%), DA-90 in 8 (11%), DAC in 11 (15%), other in 2 (4%) pts. Fifty seven (78%) pts achieved first composite complete remission (CRc=CR+CRi) after 1 or 2 courses of induction, 12 (17%) had primary refractory disease (PRD) and 2 (3%) pts died in aplasia. Median number of consolidation courses was 2 (range: 1-4). Fifty one (89%) pts with CR1 fulfill the criteria for MRD analysis after 1 or 2 courses of induction and 34 (48%) pts after consolidations. Thirty four pts had 2 timepoints evaluation: after induction and at the end of consolidation courses. MRD+ was reported in 35 (68%) of pts after induction (median 0.5; IQR 0.25-0.85) and in 19 (52%) of pts at the end of consolidations (median 0.64; IQR 0.22-1.99). Analysis of 4 pts groups was performed: Group 1.: MRD+ after induction and at the end of consolidations (persistent MRD+)(n=16; 47%); Group 2.: MRD+ after induction with conversion to MRD- at the end of consolidations (n=6; 18%); Group 3.: MRD- after induction with conversion to MRD+ at the end of consolidations (n=2; 6%); Group 4.: MRD- after induction and at the end of consolidations (persistent MRD-)(n=10; 29%); Baseline clinical characteristics were similar between 4 groups regarding age, FLT3-ITD and FLT3-TKD frequency, FLT3-ITD allelic ratio (AR), WBC, PLT, peripheral blood and bone marrow blast percentage, AML type: de novovs sAML vs tAML (p-values > 0.05). The probability of 1- year RFS was significantly lower in pts with persistent MRD+ (group 1.) vs group 2. vs 3. vs 4. (27% vs 83% vs 50% vs 78%; p=0.034, respectively). Relapse rate after 1 year was in group 1. vs 2. vs 3. vs 4.: 73% vs 16% vs 50% vs 20% (p=0.015), respectively. The shorter OS, but insignificant, was noted in group 1. vs 2. vs 3. vs 4. (p=0.49). A univariate analysis revealed that allo-HSCT (hazard ratio [HR] 0.345; 95% confidence interval (CI), 0.152-0.784; p=0.011) and male sex (HR, 0.433; 95% CI, 0.217-0.861; p=0.017) are predictors for longer OS. MRD- at the end of consolidations (HR, 0.211; 95% CI, 0.066-0.669; p=0.008), persistent MRD- (HR, 0.252; 95% CI, 0.070-0.909; p=0.035), allo-HSCT (HR, 0.416; 95% CI, 0.183-0.947; p=0.0368) are predictors for longer RFS. However, older age (HR, 1.049; 95% CI, 1.018-1.081; p=0.0017) and higher WBC (HR, 1.005; 95% CI, 1.002-1.008; p=0.0022) are predictors for shorter RFS. Conclusions: We observed high rate of CR1 MRD+ AML FLT3 pts after induction (68%) and at the end of consolidations (52%). Significantly lower RFS and higher relapse rate, but not OS, were noted in pts with persistent MRD+ in comparison to pts in other MRD groups. Longer follow-up period and larger studies are necessary to confirm our preliminary findings.

Genetic Predictors of Anthracycline Mediated Cardiomyopathy with Induction Chemotherapy in Acute Myeloid Leukemia (AML)

Introduction: Anthracycline induced cardiomyopathy (CMP) is a concern in AML patients (pts) induced with "7+3” (7 days of cytarabine and 3 days of an anthracycline) or liposomal cytarabine/daunorubicin (CPX-351, Vyxeos). However, it is not well understood (i) how common anthracycline CMP with the availability of routine echocardiography for baseline CMP screening and (ii) how often post induction CMP is the reason for not pursuing a potentially curative allogeneic stem cell transplant (allo-SCT). In addition, while it is known that the cumulative anthracycline dose and preexisting left ventricular dysfunction are risk factors for anthracycline mediated CMP, it is not known whether mutations recurrently mutated in myeloid neoplasms predict risk for anthracycline mediated CMP. Methods: AML pts treated at Dana-Farber Cancer Institute (2014-2022) with 7+3 or Vyxeos induction were included if they met the following criteria: (i) pre and post induction chemotherapy echocardiogram to assess the left ventricular ejection fraction (LVEF) and (ii) comprehensive next generation sequencing was obtained prior to treatment. Post induction CMP was defined as LVEF < 50%. We recorded cardiovascular comorbidities including hypertension (HTN), diabetes mellitus (DM), hyperlipidemia (HLD), coronary artery disease (CAD), severe valvular disease and smoking. Continuous variables were summarized as median (range, R), while categorical variables were reported as frequency (percentage). Univariable and multivariable regression analysis was performed to identify predictors of post induction CMP. Results: A total of 422 pts were included; 37 patients (8.8%) developed post induction CMP (Table 1). There were no statistical differences between age, AML subtype, prior cancer therapy and cumulative anthracycline dose (for prior cancer therapy and induction chemotherapy) between pts with and without post induction CMP. Only 3 pts in this cohort (0.7%) had an abnormal LVEF (<50%) pre induction arguing for a highly preselected pt population thought to be fit enough to receive anthracycline containing induction chemotherapy. The post induction LVEF was 43% (R 20-48%) and 60% (R 50-75%) for patients with and without post induction CMP (p<0.001); this corresponded to an absolute decrease in LVEF post induction compared to pre-induction of -18% and -3%, respectively (p<0.001). While 73% of pts without post induction CMP received an allo-SCT, only 46% of pts with post induction CMP received an allo-SCT (p<0.001). However, in only 4/20 pts with post induction CMP who did not receive an allo-SCT (20%) was the emergent CMP the sole reason for not pursuing an allo-SCT. In the other 16/20 pts, other medical reasons were the reason for not pursuing an allo-SCT including sepsis/fungal infection (7 pts), active disease (3 pts), allo-SCT not indicated given favorable genetics (2 pts) and other reasons (4 pts). In univariable and multivariable analysis, age, sex, cardiovascular risk factors and cumulative anthracycline dose did not predict an increased risk for anthracycline mediated CMP (Table 2). While myeloid mutations commonly seen in patients with clonal hematopoiesis (DNMT3A, TET2, ASXL1) did not predict an increased risk for CMP, presence of a JAK2 V617F mutation predicted a significantly increased risk of CMP in univariable (hazard rate [HR] 5.57, 95% CI: 1.14-22.1, p=0.019) and multivariable analysis (HR 5.91, 95% CI: 1.18-24.1, p=0.017). Interestingly, JAK2 V617F transgenic mice have been shown to develop cardiac hypertrophy and collagen fibrosis (Shi et al. Journal of Hematology & Oncology 2014) arguing for an underlying biological effect of JAK2 mutations on cardiac function. Conclusions: In a selected pt population with a normal pre-induction LVEF (99.3% of pts), 8% of pts developed post-induction CMP, however, in only 4/123 pts (3%) this was the sole reason for not receiving an allo-SCT. While cardiovascular risk factors and cumulative anthracycline dose were not predictive of post induction CMP, presence of a JAK2 V617V mutation (but not other myeloid mutations) was associated with an increased risk for anthracycline CMP. This association is intriguing as it could potentially help with patient selection at higher risk for anthracycline CMP (e.g. consideration of anthracycline free induction in JAK2 mutated pts). However, this will require validation in a larger patient cohort. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Time to Count Recovery after Post-Remission Chemotherapy in AML Patients

Background Longer time to achieve complete remission (CR) and recover counts after initial induction chemotherapy in acute myeloid leukemia (AML) patients is associated with decreased overall survival (OS) and relapse-free survival. Prolonged time to count recovery is associated with increased risk of infection and bleeding, and can result in delay of planned subsequent therapies including further chemotherapy or allogeneic transplant. While CR with count recovery after induction chemotherapy typically occurs within 4-5 weeks, there is a paucity of data for count recovery after post-remission (also known as consolidation) chemotherapy. We sought to investigate the time to neutrophil and platelet recovery after the first cycle of consolidation chemotherapy and thereby to identify optimal post-remission chemotherapy regimens. Methods We retrospectively identified adults over 18 years with newly diagnosed WHO-defined AML/high grade myeloid neoplasms (>10% blasts) who received high intensity induction chemotherapy (cladribine, cytarabine, mitoxantrone, and G-CSF, also known as CLAG-M or GCLAM) between 5/1/2014 and 12/31/2019. Patients with variations to the CLAG-M backbone such as sorafenib, midostaurin, gemtuzumab ozogamicin, and decitabine were included as well. This study was approved by the local Institutional Review Board. Consolidation treatment was defined as the first cycle of therapy given once patients achieved CR in marrow by standard criteria and divided into 3 main types for analysis: CLAG-M, CLAG-M without mitoxantrone (CLAG or GCLA) and high dose cytarabine (HiDAC). Patients who did not receive post-remission therapy with these regimens (n=23) or had refractory disease/died before consolidation therapy (n=180) were excluded from analysis. Many patients were enrolled on a single-center clinical trial of CLAG-M with dose-escalated mitoxantrone (NCT02044796). The primary endpoint was evaluation of the number of days from the start of consolidation chemotherapy to the day when absolute neutrophil count (ANC) > 1,000/ml (defined as neutrophil recovery) and platelet count > 100,000/ml (defined as platelet recovery). Early death was defined as death within 28 days of receiving consolidation therapy. Results We identified 307 patients who met our inclusion criteria; of these, 207 patients (67%) received CLAG therapy, 60 patients (20%) with CLAG-M and 40 patients (13%) with HiDAC. Compared to HiDAC, the median age of patients who received CLAG or CLAG-M was lower (p=0.013). The majority of patients were treated off study in all groups. The highest proportion of patients treated on study received CLAG therapy (36%, p=0.03). Early death was a rare event overall (1% for CLAG; 2% for CLAG-M and HiDAC), and no significant differences in ELN 2017 risk, performance status, baseline WBC, platelets, creatinine, albumin, or TRM score were identified among the three groups. Median time to neutrophil recovery was 36 days for HiDAC, 37 days for CLAG, and 50.5 days for CLAG-M (Figure 1A). Median time to platelet recovery was 48 days for HiDAC, 52 days for CLAG, and 94 days for CLAG-M. In multivariable cause-specific hazard regression models controlling for age and study enrollment, no differences were noted between CLAG and HiDAC in time to neutrophil recovery (hazard ratio [HR] 1.2, 95% confidence interval [CI] 0.81-1.76), platelet recovery (HR 1.08, 95% CI 0.71-1.64), or both neutrophil and platelet recovery together (HR 1.06, 95% CI 0.69-1.61). When compared to HiDAC, CLAG-M was associated with a trend towards longer time to neutrophil recovery (HR 0.69, 95% CI 0.43-1.09), platelet recovery (HR 0.73, 95% CI 0.44-1.21), and both neutrophil and platelet recovery together (HR 0.68, 95% CI 0.41-1.13). Controlling for age and study enrollment status, CLAG-M was associated with significantly worse 8-year OS compared to HiDAC (p=0.030), but no significant difference was identified between CLAG and HiDAC (p=0.99) (Figure 1B). Conclusions Post-remission therapy with CLAG is another viable alternative to HiDAC with no significant differences in neutrophil recovery, platelet recovery, and OS. Early death was uncommon for all three groups, but a post-remission course of CLAG-M was associated with decreased OS. Future work will examine the effect of particular cytogenetic and molecular markers on count recovery after post-remission courses. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Phase I Study of Ixazomib with Conventional Chemotherapy in the Treatment of Acute Myeloid Leukemia in Older Adults

Introduction: Outcome in acute myeloid leukemia (AML) for patients aged >60 years is poor with a median survival of approximately 11 months. Targeting the proteasome in AML is attractive, since leukemia stem cells demonstrate sensitivity to proteasome inhibition in preclinical models, perhaps through down regulation of nuclear NF-KB or MCL-1 through stabilizing effects on NOXA. AML cell lines are susceptible to synergistic cytotoxicity when bortezomib, a proteasome inhibitor, is combined with daunorubicin and cytarabine. We have shown that adding bortezomib to standard treatment in AML results in a high remission rate. A newer generation proteasome inhibitor, ixazomib, is less frequently associated with neurotoxicity, and, therefore, was selected for combination with conventional chemotherapy in this phase I trial. The primary objective of this study was to determine the recommended phase II dose (RP2D) of ixazomib in combination with intensive induction and consolidation chemotherapy for AML. A secondary objective was to determine if the level of CD74 in blasts correlated with response, since prior studies showed that CD74 may be a poor prognostic indicator, but its effect might be diminished with proteasome inhibition. Methods: Adults >60 years of age with newly diagnosed AML were screened for eligibility. Patients with secondary AML were eligible, including those with prior hypomethylating agent (HMA) therapy for myelodysplastic syndromes (MDS). We excluded those with promyelocytic leukemia. There were 2 phases in this study. In the first phase (A), the induction treatment consisted of the following: cytarabine 100 mg/m2/day by continuous IV infusion, Days 1-7; daunorubicin 60 mg/m2/day IV, Days 1, 2, 3, and ixazomib was provided orally at the cohort dose, Days 2, 5, 9, and 12. Consolidation or transplant in this phase was at the discretion of the treating physician. In the second phase (B), induction was administered with the established RP2D of ixazomib in phase A. All patients were to be treated with the following consolidation: cytarabine at 2 g/m2/day, days 1-5 with ixazomib on days 2, 5, 9, and 12 at the cohort dose for consolidation. A classical 3 + 3 patient cohort dose escalation design was used to determine whether the dose of ixazomib could be safely escalated in 3 cohorts (1.5 mg/day, 2.3 mg/day, 3.0 mg/day), initially in induction (phase A) and subsequently in consolidation (phase B). Secondary objectives included rate of complete remission (CR), disease-free survival (DFS), overall survival (OS), and outcome relationship with CD74. Results: Thirty-nine patients were enrolled, including 15 (38%) patients with secondary AML, either with antecedent myeloid malignancy or therapy-related AML. Twenty-six patients (67%) were male, and the median age was 68 years (range 61-80 years). There were no grade 5 toxicities attributed to study drug. Four patients died before day 30 with persistent leukemia, 3 of whom were replaced for assessment of the MTD. Three other patients were not evaluable and were replaced. Nearly all grade 3 and 4 toxicities were hematologic (Table). There was 1 DLT (grade 4 platelet count decrease extending beyond Day 42). There were no grade 3 or 4 neurotoxicity events attributable to ixazomib. Among the 38 patients evaluable for response, 26 achieved CR, and 2 achieved CR with incomplete count recovery (CRi), for a composite remission rate (CCR) of 74%. Among the 15 patients with secondary AML, 9 achieved CR and 2 achieved CRi, for a CCR of 73%. The median OS for the 39 patients is 40.8 months [95% CI, 17.6, Inf]. The 18-month OS estimate was 63% [95% CI, 49-80%]. Of note, 30 patients underwent stem cell transplantation. There was no significant association between level of CD74 expression on blasts at baseline and response. Conclusions: The highest dose level (3 mg) of ixazomib planned for induction and consolidation in this trial has been reached safely and is the recommended phase 2 dose for both. Notably, to date, no grade 3 or 4 neurotoxicity has been encountered. The remission rate for this regimen in this older adult population appears favorable. With ixazomib added in treatment, we saw no association of response rate with level of CD74 in blasts. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Single-Cell Proteomic Analysis Defines Metabolic Heterogeneity in Response to Venetoclax in AML

Acute myeloid leukemia (AML) is among the deadliest blood cancers with over 10,000 patients dying annually in the U.S. Despite high rates of complete remission after conventional frontline genotoxic chemotherapy, patient prognosis remains poor with a 5-year overall survival of only 28%, which is largely attributable to frequent relapses. The standard chemotherapy for AML has changed little during the past 40 years. However, several new drugs have been approved by the FDA over the last 10 years including venetoclax (VEN), BH3 mimetic protein that selectively inhibits the anti-apoptotic function of BCL2. Combining VEN with the hypomethylating agent azacytidine (AZA) or with low-dose cytarabine (AraC) demonstrated promising results, leading to approval of these combinations by the FDA. However, durable response remains a challenge as resistance has emerged. Metabolic flexibility and intratumoral heterogeneity (both genetic and non-genetic) are key components of resistance. Resistance to VEN combination therapies has implicated alternative anti-apoptosis proteins such as MCL1, monocytic differentiation state, and remodeling of mitochondrial electron transport chain complex I. TP53 or RAS mutations are also associated with resistance. To better understand the interplay between differentiation state, metabolism, and signaling pathways in resistance to VEN and its combinations, we analyzed 36 primary AML samples (31 adult, 5 pediatric) and 2 healthy bone marrow controls using single-cell mass cytometry after ex vivo treatment for 24h with VEN, AraC, AZA and VEN+AraC and VEN+AZA. Across two antibody panels we measured myeloid phenotypic markers, key signaling pathways, transcription factors and metabolic proteins relevant to glycolysis, TCA cycle, fatty acid oxidation, amino acid transport, and mitochondrial dynamics, for a total of 76 unique markers. For more than 80% of the patients, we observe, at baseline, highly metabolic subpopulations with high expression of ATPA5, a subunit of mitochondrial ATP synthase, and glutathione synthetase (GSS), necessary for redox homeostasis as well as strong expression of mitochondrial proteins related to oxidative phosphorylation and TCA cycle. A small subset of these cells also highly express glycolytic enzymes, in particular enolase 1 (ENO1) and lactate dehydrogenase (LDHA) which converts pyruvate to lactate. This demonstrates the presence of cells with dual glycolytic and oxidative metabolism possibly reflecting a high demand for NAD+ to support oxidation reactions. These metabolic features do not correlate with specific phenotypic markers and is highly variable between patients. As expected, ex vivo treatment with VEN eradicates more immature subpopulations (CD34+ and/or CD117+) while sparing monocytic populations. In general, cells with the highest levels of BCL2 respond well to VEN (Panel A). However, defining populations solely with phenotypic proteins fails to adequately identify persistent and emerging populations after VEN or its combinations. Instead, clustering based on metabolic pathways identifies persistent or emerging populations. In several patients, expression of mitochondrial cristae-shaping protein (OPA1) and NADPH-producing enzymes isocitrate dehydrogenase (IDH1) or glucose-6-phosphate dehydrogenase (G6PD) defines BCL2+ subpopulations that persist through VEN treatment, likely through maintenance of mitochondrial integrity. In other patients, we observe selection of cells expressing monocarboxylate transporter 1 (MCT1), which facilitates lactate uptake, suggesting these cells undergo metabolic reprogramming to counteract the decrease in amino-acid uptakes following VEN. Interestingly, 4 of the 5 pediatric AML samples demonstrated VEN-resistant subpopulations characterized by co-expression of glucose transporter GLUT1, fatty acid transporter CD36, and alternative anti-apoptotic protein BCL-xL (Panel B). Very little is known about metabolic dependencies in pediatric AML and VEN is an emerging therapy in this patient group. Altogether, our data indicate that single-cell metabolic analysis may better organize intratumoral heterogeneity in AML and enables discovery of new pathways defining resistance or persistence to VEN and its combinations. Further analyses and integration of clinical data including mutational patterns are underway and will be presented. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Improved Outcomes in Acute Myeloid Leukemia Patients Receiving 7+3 Induction By Using Protocolized Antifungal Prophylaxis in a Community Setting

Introduction: Invasive fungal infections (IFI) are a leading cause of mortality in patients with acute myeloid leukemia (AML) undergoing induction chemotherapy including "7+3” regimen of cytarabine and daunorubicin.1 Posaconazole improves survival and reduces IFI rates in comparison with fluconazole.2 The aim of our study was to compare outcomes of patients receiving induction chemotherapy for AML at our institution before and after implementation of a priority matrix (PM) including standardized antifungal prophylaxis. Our primary endpoint was incidence of IFI, and our secondary endpoints were mortality at 30 days and 1 year. Methods: All patients admitted with AML and receiving 7+3 induction chemotherapy at Gundersen Health System between January 2013 and January 2022 were included in our study. Patients were assigned either to Pre-PM or Post-PM group (whether induction was started before or after January 1, 2019, respectively). The priority matrix (Figure) included mandatory treatment with appropriate prophylaxis (posaconazole /voriconazole), patient education, electronic health record (EHR) updates, standardized work up for refractory fevers, and other optimization practices. Antifungal agent was given starting on day 8 after initiation of induction until resolution of neutropenia, defined as an absolute neutrophil count >500/uL. Treatment-related mortality rates (TRMR) and Charlson Comorbidity Index (CCI) were calculated at time of diagnosis. Statistical analyses using chi-square, Fisher exact, Wilcoxon rank sum tests, and Cox proportional hazards were done in SAS version 9.4. Results: The study population consisted of 37 patients: 23 in the Pre-PM group (prior to Jan 1, 2019) and 14 in the Post-PM group. The population was predominantly white, non-Hispanic with a median age 63 years, and was 60% male. Groups were similar with regard to median age, sex, TRMR, and CCI. Of the 23 Pre-PM patients, 6 received fluconazole. All patients in the Post-PM group received prophylaxis-1 with voriconazole, and 13 with posaconazole. Six Pre-PM patients (26%) developed IFI, compared with 1 Post-PM patient (7%; p=0.22). Five of the 6 Pre-PM patients who received fluconazole developed IFI, as did 1 Post-PM patient who received posaconazole (p<0.001). Four (17%) Pre-PM patients, none of whom received fluconazole died within 30 days, and there were no deaths in the Post-PM group (p=NS). Fifteen (65%) Pre-PM patients died within 1 year (5 had received fluconazole prophylaxis), compared with 3 (21%) Post-PM patients. Mortality rates were not significantly different between groups at 30 days (p=0.22)); however, mortality at 1 year was significantly higher in the Pre-PM group (log rank p=0.004), including in those receiving fluconazole (log rank p=0.0005). Conclusions: Our study shows significantly improved outcomes with use of a standardized protocol in AML patients receiving 7+3 induction by using posaconazole over fluconazole per our PM intervention. We reduced IFI rates to our goal of <10% in AML patients and improved 30-day and 1 -year survival at our institution, rates comparable to national averages. Because community health care facilities are increasingly treating patients with AML, we share our protocol to help improve care in this setting. References 1Hsu A. et al. Supportive Care in Cancer, . 2021;29(2):707-712. 2Cornely OA, et al. N Engl J Med. 2007;356:348-359 Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Inhibition of Stearoyl-CoA Desaturase Has Anti-Leukemic Properties in Acute Myeloid Leukemia

Metabolic rewiring, a hallmark of acute myeloid leukemia (AML), contributes to the development of resistance to intensive chemotherapy and has been shown to play an essential role in leukemic cell maintenance. Several metabolic alterations have been described in AML, such as dependence on amino acids to fuel oxidative phosphorylation or ability of leukemic cells to switch energy dependence to fatty acid oxidation in response to treatment. However, little is known about the functional significance of the fatty acid synthesis (FAS) pathway in AML. Here we have identified stearoyl-CoA desaturase (SCD), a key enzyme responsible for the conversion of saturated fatty acids (SFA) into monounsaturated fatty acids (MUFA), as a novel therapeutic target in AML. High SCD expression predicts worse survival across several patient datasets, even after correction for gender, age and AML European LeukemiaNet risk category. Moreover, genetic and chemical inhibition of SCD reduces growth and induces cell death in AML cells. Since targeting SCD with currently available inhibitors has been challenging because of their toxicity profile in vivo, we have accessed a novel pharmacological SCD inhibitor with a more favorable toxicity profile, SSI-4 (Modulation Therapeutics Inc., Morgantown, USA). SSI-4 reduces viability in several human and mouse AML models in vitro and in about half of the 36 primary AML samples tested ex vivo. Moreover, SSI-4 displays anti-leukemic effects in AML murine models and patient-derived xenografts (PDX). Since we could not correlate susceptibility to SCD inhibition with any genetic characteristic of AML cells, we aimed to determine the molecular basis of cell sensitivity using phosphoproteomic, proteomic and transcriptomic approaches coupled with metabolic analyses of sensitive and resistant cell lines and primary AML cells. Sensitivity to SCD inhibition directly correlates with rate of de novo FAS, as measured by fatty acid labeling with 13C-glucose. Moreover, modulation of FAS by the AMPK signaling activity dictates sensitivity to SCD inhibition and AMPK activation rescues the anti-leukemic effects of SSI-4. The anti-leukemic effects of SCD inhibition are secondary to the induction of SFA mediated lipotoxicity, as demonstrated by the increased sensitivity of previously resistant cells to SSI-4, when grown in the presence of the SFA palmitate. Conversely, growing cells in the presence of the MUFA oleate, as well as inhibition of FAS by targeting enzymes upstream of SCD, results in resistance to SSI-4, thus confirming that the increased SFA/MUFA ratio drives leukemic cell death. SFA mediated lipotoxicity leads to both increased lipid peroxidation and activation of the unfolded protein response (UPR), namely its PERK branch, which in turn leads to apoptotic cell death. Indeed, inhibition of PERK, but not of other branches of UPR, rescues SCD-mediated cytotoxicity. Despite causing disease debulking in vivo, SSI-4 does not prolong survival in murine AML models as a single agent and the toxic effects of SSI-4 are decreased when AML cells are grown in co-culture with stroma, suggesting a protective role of tumor microenvironment. However, we consistently detect increased lipid peroxidation and DNA damage both in vitro and in vivo following SCD inhibition. We therefore combined SSI-4 with doxorubicin, a known inducer of lipid peroxidation and DNA damage, which is routinely used in AML induction therapy. Indeed, both genetic depletion and pharmacological inhibition of SCD renders AML cells more sensitive to doxorubicin, and addition of SSI-4 to a standard AML chemotherapy protocol consisting of doxorubicin and cytarabine significantly extends survival in AML mouse models. In summary, we identify and validate SCD as a therapeutic target in AML. The novel SCD inhibitor SSI-4 displays anti-leukemic properties both in vitro and in vivo across different AML models and particularly when combined with standard chemotherapy while showing minimal toxicity in vivo. We show that sensitivity to SCD inhibition is driven by metabolic rather than genetic AML features, thus making this therapeutic approach potentially applicable across several AML subtypes, including high risk ones. Finally, the mechanism of toxicity following SCD inhibition suggests that this can be further enhanced by modulating the levels of SFA/MUFA through dietary interventions or by combining it with DNA damaging agents. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Targeting the Mevalonate Pathway in the Mitochondria-Dependent Chemotherapy Resistance of TP53 Mutant Acute Myeloid Leukemia

Acute myeloid leukemia (AML) bearing mutations in the TP53 tumor suppressor gene is the most fatal of AMLs with a two-year overall survival between 0-15%. Patients with TP53 mutant (MT) AML typically respond to initial therapy but quickly relapse and die of disease due to chemotherapy resistance. We have undertaken to understand the mechanisms of chemotherapy resistance in TP53 MT AML. Initially, we purified AML blasts to 99% purity using flow sorting and performed RNA sequencing on TP53 MT and wildtype samples. Gene set enrichment analysis demonstrated that TP53 MT AML patient samples were enriched in the cholesterol synthesis or mevalonate pathway. This was validated using the BEAT AML dataset. Interestingly, p53 loss and/or mutation in breast, liver, colon and pancreatic cancer models leads to a dependency on an upregulated mevalonate pathway. Despite these data, the role of the mevalonate pathway in TP53 MT AML is unknown. We have subsequently explored the role of the mevalonate pathway in TP53 MT AML chemotherapy resistance. Experiments were performed in CRISPR-engineered TP53 mutated human AML cells with isogenic controls. Treatment with DNA damaging agents and analysis for cell survival confirmed that loss of wildtype p53 function enhanced cell survival. Recent results have demonstrated that chemotherapy resistance in AML cells is associated with an increase in oxidative phosphorylation (OXPHOS), which is dynamically induced by DNA damage. We confirmed that TP53 MT AML cells increase OXPHOS after DNA damage (Figure 1). Treatment of cells with rosuvastatin, a potent inhibitor of the mevalonate pathway, blocked this increase in OXPHOS and induced chemosensitivity. Lipidomic analysis demonstrates that the increase in OXPHOS correlates with an increase in coenzyme Q10 (CoQ10), a byproduct of the mevalonate pathway. Importantly, co-treatment of cells with a soluble form of mevalonate or a downstream byproduct, geranylgeranyl pyrophosphate (GGPP), recovered OXPHOS and subsequent chemoresistance. This indicates rosuvastatin's activity is specific to the mevalonate pathway, independent of cholesterol, and dependent on the GGPP branch of the pathway. Analysis is ongoing to determine the role of GGPP in regulating the mitochondrial response to DNA damage in TP53 MT cells, including if GGPP is required for CoQ10 synthesis as this remains a controversy in the literature. Overall, this data supports a model where TP53 MT AML cells dynamically upregulate the mevalonate pathway to regulate OXPHOS and avoid DNA damage-induced cell death (Figure 2). To determine if this model is physiologically relevant, we studied a patient derived xenograft (PDX) model of TP53 MT AML cells. Engrafted mice were treated with standard AML chemotherapeutic agent, cytarabine (AraC), for five days alone or in combination with high dose rosuvastatin. Interestingly, mice sacrificed three days after completing AraC administration continue to demonstrate an enhanced OXPHOS response. This response is blunted by co-treatment with rosuvastatin. As expected, TP53 MT AML cells respond modestly to AraC alone and this response was increased with the combination therapy. Overall, these results demonstrate that TP53 MT AML requires the mevalonate pathway for chemotherapy resistance and targeting of the mevalonate pathway in combination with chemotherapy may improve clinical responses. Through detailed biochemical analysis of this mechanism, we will elucidate novel therapeutic approaches to TP53 MT AML. Figure Legend: (1) Oxygen consumption rate measured by seahorse technology in indicated cell lines and conditions. Statistics performed with unpaired T-test in GraphPad with stars indicating significance as per figure. (2) Proposed schema of mevalonate pathway dependencies in TP53 mutant (MT) AML. Bold arrows indicate increased byproduct dependency in TP53 MT AML cells treated with DNA damaging chemotherapy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Pursuing the Clonal Dynamics of Minimal Residual Disease (MRD) in Relapsed and Refractory Acute Myeloid Leukemia

Acute Myeloid Leukemia (AML) is a myelogenous malignancy that frequently relapses despite complete remission (CR) and elicits non-responsiveness (refractory) to treatment. Recent studies have emphasized that acquiring resistance to treatment and/or residual subclones bearing drug persistency such as Cancer stem cells (CSCs) or Minimal residual disease (MRD) clones can lead to relapse and treatment-refractory in AML. However, due to the AML's cytogenetic clonal heterogeneity, drug persistent MRD having leukemogenic properties and its clinical relevance have not yet been fully explained. In this study, we investigate the clonal dynamics of AML MRD by pursuing their genotypic/phenotypic changes in the individual AML patient's Bone Marrow (BM) niche. To investigate, we collected longitudinal BM samples at diagnosis (Dx), remission (CR), relapse (Rel), and treatment-refractory (Per) from two patients of relapsed/refractory AML. By bulk Whole Exome Sequencing (WES), somatic variants were analyzed, and selected four oncogenic variants (Patient #01: FLT3 D835E, WT1 R375Pfs; Patient #02: KIT D816Y, ASXL1 A722L) showing a significant change according to the treatment process. Seven blood cell fractions (4 HSPCs, Hematopoietic Stem and Progenitors: HSC/MPP, LMPP, CMP/MEP, GMP, LSC-like populations; 3 Mature leukocytes: Myeloid cells, T/B Lymphocytes) from AML patient's bone marrow samples were sorted by cell surfaces antigens. Selected AML-associated variants were detected by droplet digital PCR (ddPCR) in DNA of each sorted seven single cell fractions. In the AML patient BM, we found that the clones with an oncogenic (or likely oncogenic) variant were distributed in not only primitive cell populations with the HSPC (LSC-like) phenotype, but also mature (differentiated) cell populations such as leukocytes. These clones were not completely disappeared even after intense AML chemotherapy, and remained in minimal quantities. In our sequential analysis, some residual clones distributed in LSC-like populations exhibited the traditionally well-known MRD's character, such as repopulating LSC proportions. Furthermore, some other residual clones only in mature populations also seemed to be played a role in functional MRD resulting in the repopulation of LSCs. However, whether these residual clones in LSC-like populations or mature populations eventually induced repopulating of LSC-like fractions during AML relapse, and particularly in the relapse before an endpoint, these clones also tended to be highly enriched in LSC-like populations by 30% (based on the VAF). While the variant clones in mature populations may be the temporal salvages of AML-MRD clones (functional MRD) to survive against treatment, the variant clones in LSC-like populations might be the AML-MRDs practically contributing to AML recurrence and treatment-refractory. This approach suggests the methodology for specifying AML-MRD and pursuing its clonal evolution according to the treatment progress. This will help to improve AML risk stratification and the diagnostic methodology, enabling the preemptive detection of AML MRD at the initial diagnosis/treatment. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

AML-197 Incidence of Infectious Lung Disease in Neutropenic Patients

Immunosuppression caused by hematologic malignancies can affect all cell lines, but profound neutropenia is the main risk factor. The most common infection is pneumonia. More than 60% of neutropenic patients develop a lung infection. These infections develop in 13-31% of patients during induction chemotherapy for acute myeloid leukemia (AML). They are associated with a significantly higher mortality rate than other infectious diseases. Deduce the incidence of infectious lung disease in our neutropenic patients. This is an observational, descriptive, and prospective study carried out in the Department of Hematology and Pediatric Oncology 20 August of Casablanca, spread over a period of 10 months, from 01 May 2019 to 29 February 2020. It focuses on adult patients over 18 years of age with neutropenia (a PNN count < 2×109/L) hospitalized in the protected unit (AML and aplastic anemia) and the transplant unit, who presented an episode of infectious lung disease during the study period. We determined the incidence and studied the clinical and radiological presentation, the diagnostic steps to obtain biological and microbiological documentation, and the final evolution of these infectious episodes. Out of a total of 235 admissions, 50 episodes of infectious lung disease were identified in 49 patients, for an overall incidence of 21.28%. The most frequent phase of treatment was that of Induction in AML. Thoracic CT was performed in all patients. Bronchoalveolar lavage was performed over 9 episodes. The results were positive in 44.5% of episodes. Serum galactomannan antigenemia assay was performed in 94% of cases, it was positive in 22 (46%). The GeneXpert technique was performed in six episodes (12%), with one positive result. The probable fungal infection was the cause of these infections in 58% of cases. Bacterial pneumopathy was present in 22% of episodes. Pulmonary tuberculosis was diagnosed in only one patient. Pneumocystis was suspected in 4 episodes and viral infection was suspected in 3 episodes. The evolution was favorable in 52% of the cases. The review of the literature has shown that the establishment of an etiological diagnosis is not always possible during these infections, the treatment is essentially empirical, and with a terrible prognosis.

Comparison of Three Doses of Cytarabine Consolidation for Intermediate- and Adverse-risk Acute Myeloid Leukemia: Real World Evidence From Thai Acute Myeloid Leukemia Registry.

Intermediate or high doses of cytarabine (IDAC or HiDAC) were recommended as postremission chemotherapy for acute myeloid leukemia (AML). This retrospective study investigated the real-world outcomes of 3-different cytarabine doses from the multicenter Thai AML registry database. The intermediate- and adverse-risk AML patients (N=258) who achieved complete remission and proceeded to single-agent cytarabine consolidation were enrolled. The median relapse-free survival (RFS) using IDAC 1.5 g/m2, high-dose cytarabine (HiDAC) 2 g/m2, and HiDAC 3 g/m2 were 12.6, 11.7, and 13 months, respectively. The median overall survival (OS) using IDAC 1.5 g/m2, HiDAC 2 g/m2, and HiDAC 3 g/m2 were 34.9, 22.7, and 23.7 months, respectively. No significant difference in RFS and OS was detected between the 3 doses. Secondary AML, white blood cell > 100×109/L and the adverse-risk AML were independent prognostic factors for inferior survival (P= .008, P < .001, P= .014). Patients who completed 3 to 4 cycles of consolidation had significantly superior RFS and OS (P< .001, P< .001). Febrile neutropenia occurred in 72.9% of IDAC, 73.8% of HiDAC 2 g/m2, and 78.1% of HiDAC 3 g/m2 without statistical significance. However, the incidence of septic shock was significantly higher after HiDAC 3 g/m2 compared to IDAC regimen (8% vs. 3%, P= .037). IDAC is an appropriate regimen for postremission chemotherapy for intermediate- and adverse-risk AML. The higher dosing levels may not produce any benefits to patients and may increase incidence of septic shock. The number of consolidation cycles may impact on survivals rather than the intensity of cytarabine.

AML-191 A Single Institution Experience on Clinical Outcomes of TP-53 Mutant Acute Myeloid Leukemia (AML)

TP53 (tumor suppressor gene, 'the guardian of the genome') regulates DNA repair and cell division. TP53 mutations are observed in up to 20% of AML patients. It carries an adverse prognosis and is associated with inferior outcomes. Analyze TP53 mutations impact in AML patients. We reviewed patients with TP53 mutated AML treated at our institution. All cases of TP53 mutated AML (9 patients, 6.9%) of 130 AML patients were included. Nine patients were identified with newly diagnosed TP53 mutated AML. Fit non-APL patients received induction chemotherapy (IC) with purine analogues, cytarabine-anthracycline. Unfit patients received intensity chemotherapy (LIC) with a hypomethylating agent and venetoclax or cladribine, low dose cytarabine (LDAC) and venetoclax. Complete response (CR) rate and overall survival (OS) were analyzed. Among 130 patients with AML, we identified with TP53 mutations. 5(55%) were women. Races included Whites (n=2), Blacks (n=5) and Hispanics (n=2). Median age was 66 years (range, 41-80). Eight patients (88%) had complex cytogenetics. A coexisting IDH1 and DNMT3A mutation were present in 2 and 1 patient, respectively. 2 patients received FIA, and none achieved a CR. One patient treated with FIA developed severe neutropenic typhlitis and multiorgan failure. Unfit patients received HMA alone (n=2), HMA+ Ven (n=3), Cladribine, LDAC and Ven (n=2). Among 3 patients treated with HMA plus Ven; 2 achieved a CR. 2 patients treated with cladribine, LDAC, and Ven achieved CR after first cycle, and both remain in CR at a mean follow-up of 5 months. None received allogenic stem cell transplant (ASCT) in CR 1, but one patient underwent ASCT in CR 2 and died 2 months after transplant from graft failure and infection. Median OS in the entire cohort was 180 days (95% CI. 39.0-393.0 days). Our analysis though small in numbers seems to confirm the poor response to intense cytotoxic chemotherapy in TP53 mutant AML as described in recent medical literature (Short et al., Blood Advances, 2022). LIC is well tolerated and can be used as an effective bridging strategy to ASCT.

Membrane-Wrapped Nanoparticles for Enhanced Chemotherapy of Acute Myeloid Leukemia.

This work reports the development of a biomimetic membrane-wrapped nanoparticle (MWNP) platform for targeted chemotherapy of acute myeloid leukemia (AML). Doxorubicin (DOX), a chemotherapeutic used to treat leukemias, lymphomas, and other cancers, was encapsulated in polymeric NPs that were coated with cytoplasmic membranes derived from human AML cells. The release rate of DOX from the MWNPs was characterized under both storage and physiological conditions, with faster release observed at pH 5.5 than pH 7.4. The system was then introduced to AML cell cultures to test the functionality of the released DOX cargo as compared to DOX delivered freely or via NPs coated with poly(ethylene glycol) (PEG). The MWNPs delivered DOX in an efficient and targeted manner, inducing up to 80% apoptosis in treated cells at a dose of 5 μM, compared to 15% for free DOX and 17% for DOX-loaded PEG-coated NPs at the same drug concentration. The mechanism of cell death was confirmed as DNA double-strand breaks through a γH2A.X assay, indicating that the released DOX retained its expected mechanism of action. These findings designate MWNPs as a robust drug delivery system with great potential for future development in treatments of AML and other blood cancers.

Cecum Necrosis with Terminal Ileum Perforation Due to Invasive Fungal Infection in a Patient with Diabetes Mellitus and Acute Myeloid Leukemia: A Case Report

Introduction: Immunosuppression conditions are the leading risk factors for opportunistic fungal infections. The clinical manifestation is related to the site of infection. Gastrointestinal (GI) mucormycosis is a rare form of this disease, even in immunosuppressed patients. Case Presentation: We report rare cecum necrosis with terminal ileum perforation resulting from infiltration of mucormycosis in the cecum wall and terminal ileum mesentery in a patient with diabetes mellitus and acute myeloid leukemia (AML). During chemotherapy for AML, the patient presented diarrhea followed by constipation, severe progressive abdominal pain, and fecaloid peritonitis. Perforation of the terminal ileum was observed during the surgery. Ileostomy, right hemicolectomy, and resection of necrotic tissue were performed, and bowel mucormycosis was confirmed on histologic examination. Unfortunately, the patient expired five days after surgery. Conclusions: Gastrointestinal mucormycosis is an uncommon infection with symptoms like abdominal pain, nausea, vomiting, and melena. The mortality of GI involvement is due to perforation, peritonitis, and GI bleeding.

Burden of chemotherapy in patients with relapsed/refractory acute myeloid leukemia in the United States: a retrospective claims database study

ABSTRACT Background Real-world estimates of relapsed or refractory (R/R) acute myeloid leukemia (AML) chemotherapy episode costs are scarce. We quantified chemotherapy episode–related costs and healthcare resource use (HRU) in R/R AML. Research Design and Methods This real-world, retrospective analysis of United States claims from IQVIA’s PharMetrics® Plus database (October 2008-September 2019) identified adults with R/R AML and ≥1 chemotherapy episode. Chemotherapy episode (ie, low- [LIC] or high-intensity [HIC] chemotherapy) costs and HRU were determined using inpatient, outpatient, and pharmacy claims. Results Mean (SD) and median total all-cause healthcare costs per R/R AML chemotherapy episode were $230,799 ($300,770) and $129,117. Mean (SD) and median adjusted direct R/R AML chemotherapy episode costs were $116,384 ($151,425) and $63,298, with increases noted from the first to the second and subsequent episodes and with HIC. Hospitalizations were the major cost driver; 64.1% of patients had ≥1 hospitalization and 36% required an intensive care unit stay. Conclusions R/R AML chemotherapy episode costs were high, with higher costs reported with HIC and increasing lines of chemotherapy. Hospitalizations were a main cost driver. Novel therapies with comparable or improved effectiveness and decreased need for hospitalizations versus chemotherapy may help alleviate the clinical and economic burden of R/R AML.

Improved outcomes with 7+3 induction chemotherapy for acute myeloid leukemia over the past four decades: analysis of SWOG trial data.

We have previously shown that complete response (CR) rates and overall survival (OS) of patients with acute myeloid leukemia (AML) have improved since the 1980s. However, we have not previously evaluated how the length of first CR (CR1) has changed over this time period. To address this, we analyzed 1,247 patients age 65 or younger randomized to 7+3 arms from 5 SWOG studies: S8600 (n=530), S9031 (n=98), S9333 (n=57), S0106 (n=301), S1203 (n=261). We evaluated length of CR1 and survival after relapse from CR1 over the 4 decades these studies represent. Both length of CR1 and survival after relapse from CR1 have improved over the last four decades. The relative benefit associated with CR1 and the relative detriment associated with relapse have decreased over this period; while achieving CR1 and relapse from CR1 still have strong prognostic associations with outcomes, the magnitude of the association has decreased over time. Possible explanations for these patterns include higher CR rates with salvage therapies after relapse, more frequent use of hematopoietic cell transplant, and better supportive care.

5-Demethylnobiletin Inhibits Cell Proliferation, Downregulates ID1 Expression, Modulates the NF-κB/TNF-α Pathway and Exerts Antileukemic Effects in AML Cells.

Acute myeloid leukemia (AML) is characterized by the dysregulation of hematopoietic cell proliferation, resulting in the accumulation of immature myeloid cells in bone marrow. 5-Demethylnobiletin (5-demethyl NOB), a citrus 5-hydroxylated polymethoxyflavone, has been reported to exhibit various bioactivities, such as antioxidant, anti-inflammatory and anticancer properties. In this study, we investigated the antileukemic effects of 5-demethyl NOB and its underlying molecular mechanisms in human AML cells. We found that 5-demethyl NOB (20–80 μM) significantly reduced human leukemia cell viability, and the following trend of effectiveness was observed: THP-1 ≈ U-937 > HEL > HL-60 > K562 cells. 5-Demethyl NOB (20 and 40 μM) modulated the cell cycle through the regulation of p21, cyclin E1 and cyclin A1 expression and induced S phase arrest. 5-Demethyl NOB also promoted leukemia cell apoptosis and differentiation. Microarray-based transcriptome, Gene Ontology (GO) and Gene Set Enrichment Analysis (GSEA) of differentially expressed genes (DEGs) analysis showed that the expression of inhibitor of differentiation/DNA binding 1 (ID1), a gene associated with the GO biological process (BP) cell population proliferation (GO: 0008283), was most strongly suppressed by 5-demethyl NOB (40 μM) in THP-1 cells. We further demonstrated that 5-demethyl NOB-induced ID1 reduction was associated with the inhibition of leukemia cell growth. Moreover, DEGs involved in the hallmark gene set NF-κB/TNF-α signaling pathway were markedly enriched and downregulated by 5-demethyl NOB. Finally, we demonstrated that 5-demethyl NOB (20 and 40 μM), combined with cytarabine, synergistically reduced THP-1 and U-937 cell viability. Our current findings support that 5-demethyl NOB dramatically suppresses leukemia cell proliferation and may serve as a potential phytochemical for human AML chemotherapy.