Chemotherapy For Acute Myeloid Leukemia Research Articles

Idarubicin Versus Daunorubicin Versus Mitoxantrone for Induction Chemotherapy in Acute Myeloid Leukemia: Patient Registration Study of Turkish Society of Hematology-Acute Myeloid Leukemia Working Group

Introduction: Standard induction chemotherapy in newly diagnosed acute myeloid leukemia (AML) includes a combination of standard-dose cytarabine and an anthracycline (idarubicin [IDA], daunorubicin [DNR], or mitoxantrone [MXR]). Anthracycline selection is still not standardized, and the impact of anthracycline selection on survival and response in patients with adverse genetic risk is of interest. The study aimed to retrospectively compare the effectiveness of induction regimens with respect to anthracycline preference. Methods: The study population was recruited from the Turkish AML Registry project database based on documentation of newly diagnosed AML and induction chemotherapy with IDA, DAU, or MXR in combination with cytarabine. Patients diagnosed before 31 August 2022 were received typical “7 + 3” induction chemotherapy containing 3 days of IDA, DAU, or MXR. Results: The study included 317 newly diagnosed AML patients (median age 51; range, 18 - 79; 55.2% male). Of the patients, IDA was administered in 266 (83.9%), DNR in 42 (13.2%), and MXR in 9 (2.8%). The three anthracycline treatment groups were similar between age, gender, type of AML by the World Health Organization (WHO), and risk classification by 2017 European LeukemiaNet (ELN) when evaluated according to the baseline disease characteristics. At the time of diagnosis, although the median white blood cell levels were 19 x 10 9/L (0.4 - 355) in the IDA, 7.8 x 10 9/L (0.7 - 357.2) in the DAU, and 5.5 x 10 9/L (0.6 - 34) in the MXR therapy group (p = 0.019); the hemoglobin and platelet levels and bone marrow blast percentage were similar between the treatment groups. FMS-like tyrosine kinase-3 internal tandem duplication ( FLT3-ITD) (p = 0.561) and Nucleophosmin 1 gene ( NPM1) (p = 0.430) mutation frequencies were also similar between treatment groups. Morphological complete remission (CR) was documented in 65% of all evaluable patients. Among the patient groups, CR was 67.7% for IDA, 50% for DNR, and 55.6% for MXR (p = 0.081). In univariate analysis (Table 1), significant predictors of overall survival (OS) were age ≥60 years (p <0.001), acute leukemias of ambiguous lineage (p <0.001), presence of disseminated intravascular coagulation (DIC) (p = 0.012), and FLT3-ITD mutation (p = 0.018); no significant interaction was noted between NPM1 mutation and OS (p = 0.059). Additionally, when idarubicin was taken as a reference, there was no meaningful relationship between anthracycline type and OS (p values for daunorubicin and mitoxantrone were 0.145 and 0.356, respectively). In multivariate analysis (Table 1), age ≥60 years (p = 0.001), acute leukemias of ambiguous lineage (p = 0.007), and the presence of DIC (p = 0.040) remained significant. After a median follow-up of 29.8 months, 32.5% relapse cases were documented and similarly distributed among IDA (33.1%), DNR (31%), and MXR (22.2%) therapy groups (p = 0.771). During the same period, allogeneic hematopoietic stem cell transplantation (AHSCT) was documented in 10.9% and 26.2% of patients treated for IDA and DNR, respectively. No patient progressed to AHSCT in the MXR arm (p <0.001). In the study, 142 (44.8%) deaths were reported, and there was a 48.5%, 26.2%, and 22.2% mortality rate between the IDA, DNR, and MXR treatment groups, respectively. There was no significant difference in OS by anthracycline type in both the study cohort and age group <60 years (Figures 1A and 1B). There was also no significant difference in OS in patients with the adverse genetic risk group and <60 years age group with adverse genetic risk, according to 2017ELN (Figures 1C and 1D). The results may have been influenced by the number of patients in the treatment groups of the retrospective study and by differences in fitness levels that needed to be measured systematically. Conclusions: We are encouraged that our findings mostly agree with previously published studies and that IDA, DNR, and MXR offer comparable survival values in the research and the younger patient groups. In the future, the ever-changing treatment environment in patient groups with targetable mutations makes choosing the optimal anthracycline for induction chemotherapy in AML much more difficult.

Venetoclax Combined with HMA Versus CAG Based Chemotherapy in Acute Myeloid Leukemia: A Propensity Score Matched Analysis

Abstract Background: Venetoclax(VEN) combination with hypomethylating agent(HMA) are lower-intensity regimens with safety which are widely used for older patients with newly diagnosed acute myeloid leukemia (AML). On the other hand, regimen of cytarabine, aclarubicin and G-CSF (CAG) with or without HMA is also of low-intensity usually applied to older AML patients. The comparison of outcomes of these two regimens has not been reported. In this study, we performed a multicenter, retrospective propensity score-matched study to compare the therapeutic responses and survival outcomes of newly diagnosed AML patients with induction of HMA-VEN to those with CAG based treatment. Methods: Newly diagnosed AML patients treated either VEN/HMA or CAG with or without HMA between January 2013 and April 2023 were compared. Age at diagnosis, sex, ECOG performance status, state of fitness for intensive chemotherapy according to Ferrara criteria and ELN2017 risk group were used to construct the propensity score using logistic regression. Propensity score matching was performed in a 1:1 ratio with a calliper value of 0.02. The treatment response, relapse rate, duration of remission, overall survival (OS) were compared between the two groups. Results: A total of 98 out of 109 newly diagnosed patients treated with VEN/HMA were matched to 98 out of 159 newly diagnosed patients treated with CAG based therapy. The patients in VEN/HMA cohort were treated between February 25, 2021 and April 30, 2023. The CAG based treatment recipients were treated from January 25, 2013 to November 12, 2021. The CAG based treatment cohort which was termed as “CAG cohort” below matched closely with the VEN/HMA cohort in terms of baseline characteristics and propensity scores (Table1). The median age was 62 years (range, 52-67) in VEN/HMA cohort and 63 years (range,52-68) in CAG cohort, and the median follow-up period was 6.3 months (range,3.2-14.0) in VEN/HMA cohort and 12 months (range,3.8-28.3) in CAG cohort. Patients treated with VEN/HMA achieved a significantly higher rate of CRc (82.4% vs 60.6%, P=0.002) compared to CAG cohort, with 36.5% in CR, 45.9% in CRi in VEN/HMA cohort and 30.3% in CR, 30.3% in CRi in CAG cohort. There was no statistic difference of the CRc rate between CAG versus CAG plus HMA(35.7%，n=14 vs 60.5%,n=76, p=0.085). CRc in the VEN/HMA and CAG cohort were 100% vs 85.7(p=0.483), 75.9% vs 46.9%(p=0.021), 64.3% vs 45.2%(p=0.079) in the ELN2017 favorable, intermediate and adverse risk group, respectively. The MRD-negative remission rate was higher in VEN/HMA cohort compared to CAG cohort (85.5% vs 61.2%, p= 0.003). The MRD-negative remission rate in the VEN/HMA and CAG cohort were 91.6% vs 80.0%(p=0.571), 88.0% vs 66.6%(p=0.188), 83.9% vs 45%(p=0.003) in the ELN2017 favorable, intermediate and adverse risk group, respectively(Table2). Responses of patients with different mutations were analyzed and ASXL1 predicted higher CRc rate with VEN/HMA treatment compared to CAG based treatment (92.3% vs. 40%, p= 0.019). The median OS was not reached in VEN/HMA cohort and 18 months in CAG cohort(p=0.16). Patients who achieved CRc had longer survival than those without CRc (not reached vs 6.4m, p<0.001). Patients who got MRD negative remission had better survival than those only with MRD positive remission (not reached vs 11.8m, p=0.0002). Patients who underwent allogeneic HSCT had longer survival than those didn't receive transplantation (not reached vs 12.3m, p<0.001). Conclusions: With propensity score-matched analysis, our data show that VEN/HMA demonstrates better treatment response than CAG regimen in patients with newly diagnosed AML. The survival outcome benefits from MRD negative response and allogeneic HSCT. Disclosures No relevant conflicts of interest to declare.

Preclinical Evaluation of Bisantrene As Single Agent and in Combination with Decitabine for Acute Myeloid Leukemia

Anthracyclines, particularly doxorubicin and idarubicin, together with cytarabine, have comprised standard of care induction chemotherapy in acute myeloid leukemia (AML) for almost 4 decades. Although 60% of patients achieve remission, the majority relapse within 1-2 years. As such, outcomes in AML remain poor, with overall 5-year survival around 27%. In elderly AML patients the situation is worse, with 80% dying within one year of diagnosis. Toxicity of induction therapy is a major barrier to treatment success, precluding many unfit and elderly patients. Hypomethylating agents (HMA; azacytidine, decitabine) provide a less toxic alternative and have improved treatment options for the unfit. However, only 50% of patients respond to HMA therapy and most eventually acquire resistance, resulting in relapse. Approaches that reduce the toxicity of induction therapy and improve the efficacy of HMA treatment are emerging, e.g. combinations with Venetoclax. Nevertheless, novel combination strategies that improve outcomes in certain mutation subtypes need to be explored. Bisantrene, an anthracene derivative developed over 4 decades ago as a less cardiotoxic chemotherapy alternative to anthracyclines, shows broad activity across multiple solid and haematological malignancies. Several clinical studies in the 1980s showed bisantrene is an effective AML salvage therapy, producing response rates up to 50% without accompanying cardiotoxicity (Rothman J., 2017 Int J Cancer Res Ther;2(2):1-10) In a recent investigator-led Phase II trial of heavily pre-treated relapsed/refractory AML patients, 1/10 achieved a complete remission and 3/10 patients achieved partial remission. Interestingly, all responders were characterised by extramedullary disease (Cannani et al., 2020 Eur J Haematol 2021;106:260-266). We postulate that bisantrene may represent a suitable candidate for combination with HMA in patients unfit for standard induction chemotherapy. To explore this idea, we evaluated the in vitro and in vivo effects of bisantrene both alone and in combination with decitabine. The in vitro activity of bisantrene was initially assessed in a range of human and mouse AML cell lines covering the major molecular and clinical subtypes. All cells were sensitive to bisantrene, showing IC 50 values in the range 16-563 nM. FLT3-ITD + cells in particular were sensitive, while NRAS, KRAS and KIT mutant lines were also responsive. When tested against primary patient AML samples, 15/49 (30.6%) responded strongly to bisantrene treatment ex vivo over the dose range 0.1-1 µM. Bisantrene was shown to induce G1 accumulation and dose-dependent apoptosis in the FLT3-ITD + cell line, MOLM13. When tested in combination with decitabine, pre-treatment with decitabine for 24 h followed by decitabine plus bisantrene for 3 days produced synergistic cytotoxicity in MOLM13, MV4-11 and OCI-AML3 cells. Bisantrene and decitabine together resulted in S phase accumulation in MOLM13 cells and synergistic induction of apoptosis. The in vivo efficacy of bisantrene alone and in combination with decitabine were examined using the MOLM13- luc cell line and a patient derived xenograft (PDX; AML16) (FLT3-ITD +, NPM1, IDH2 and WT1 mutant) in NSG mice. Bisantrene (10 mg/kg i.v. twice/week) significantly reduced leukemic burden and increased median survival compared to vehicle control in MOLM-13- luc engrafted mice, and significantly reduced leukemic burden and increased median survival in a dose and schedule-dependent manner (2.5mg/kg and 5mg/kg, twice or three times weekly) in the PDX model. The combination of bisantrene (5 or 10 mg/kg twice weekly) and decitabine (0.2 mg/kg i.p. 5 days/week) significantly improved survival in MOLM13- luc (Figure 1) and PDX AML16 (Figure 2) engrafted mice, respectively, relative to vehicle control and each single agent. The combination also reduced leukemic infiltration to extramedullary sites (spleen, liver, uterus, brain). These data support that addition of bisantrene to HMA backbone therapy may provide an important new treatment strategy in AML. A prospective Phase Ib/II trial is being planned to evaluate this new therapeutic approach.

MRD Directed Treatment Intensification with Either FLAG-Ida or DA-Cladribine Improves Survival in Older AML Patients: Results from the NCRI AML18 Randomised Trial

Background Following intensive chemotherapy in acute myeloid leukemia (AML), residual disease, assessed by failure to achieve a remission (CR/CRi) or the presence of measurable residual disease (MRD) in remission identifies a poor risk group of patients. In the NCRI AML16 trial for older adults (>60yrs), patients who were MRD+ve by flow cytometry in their remission bone marrow after course 1 had significantly poorer survival (26% at 3yrs vs 42% if MRD-ve) due to a higher risk of relapse (Freeman et al JCO 2016). These results suggested that flow cytometric MRD after course 1, by identifying patients who have a poor outcome with standard therapy, could be used to risk stratify for further treatment. However, although not infrequently used, it is uncertain whether chemotherapy intensification is of benefit to older adults with residual disease. In the AML18 trial we therefore conducted a course 2 randomization to evaluate MRD directed chemotherapy intensification in older adults. Methods AML18 patients who did not achieve MRD negativity after their first course (either not in CR/CRi or MRD+ve or MRD unknown) were randomized to either continue treatment with up to two courses of standard DA (Daunorubicin, AraC) (DA3+8 followed by DA2+5) or to receive up to 2 courses of intensified chemotherapy:- either FLAG-Ida or DA with Cladribine (DAC) (DA3+8, followed by DA2+5 both including Cladribine 5 mg/m 2 x 5 days). Course 1 had comprised DA (3+10) with 0, 1 or 2 doses of gemtuzumab ozogamicin. FLAG-Ida was dose reduced for patients over 70yrs and in course 3 for all patients (Fludarabine from 30mg/m 2 days 1-5 to 25mg/m 2 days 1-4, Idarubicin from 8mg/m 2 days 3-5 to 5mg/m 2 days 2-4). The DAC randomization was closed May 2019 due to drug supply issues. The primary endpoint was overall survival (OS). Rate ratios (RR) were used when appropriate to account for non-proportional hazards effect. Secondary endpoints included conversion to MRD negativity (defined as undetectable MFC-MRD) following course 2. Results Between Nov 2014 and Jan 2023, 523 patients (median age 67yrs) entered this randomization (193 DA, 191 FLAG-Ida, 139 DAC) following course 1 response assessment. Of these patients 164 (31%) were not in CR/CRi, 260 (50%) were in CR/CRi MRD+ve and the remaining 99 (19%) were in CR/CRi but with MRD unknown (due to an absence of a leukaemia-associated-immunophenotype at diagnosis or inadequate/missing samples). 99/477 (21%) of patients had adverse risk cytogenetics. All characteristics were balanced between arms. Median follow-up was 51 months. Following course 2, 47% (78/164) of those not in CR/CRi after course 1 converted to CR/CRi within 50 days: 55%, 57%, 34% for DA, DAC and FLAG-Ida respectively (DA vs DAC P=0.63, DA vs FLAG P=0.015). Of 282 patients providing MRD results after both course 1 and 2, 51% (60/117), 63% (50/79) and 58% (50/86) converted to MRD negativity after DA, DAC and FLAG-Ida respectively (DA vs DAC P=0.16, DA vs FLAG P=0.33). Greater hematological toxicity was seen with DAC or FLAG-Ida compared to DA (P<.001 for both platelet and neutrophil recovery). Day 60 mortality was increased in patients randomized to FLAG-Ida (9% vs 4% with DA and 4% with DAC, P=0.032). In total, 213 (41%) patients underwent allogeneic SCT (DA 42%, DAC 47%, Flag-Ida 35%). OS at 5yrs was 27%, 32% and 32% for DA, DAC and Flag-Ida respectively (DAC vs DA HR=0.82 95%CI 0.62-1.09, P=0.174; FLAG-Ida vs DA HR=0.90 95%CI 0.70-1.16, P=0.407). In subgroup analyses, comparing patients with known and unknown MRD status, there was no detectable survival benefit from intensification for MRD unknown patients (FLAG-Ida vs DA RR 1.52 95%CI 0.92-2.50, P value = 0.105; DAC vs DA RR 1.10, 95%CI 0.81-1.45, P value = 0.549). In a sensitivity analysis, excluding patients with unknown MRD, there was a significant OS benefit for both DAC (OS at 5yrs, 32% vs 22% for DA; RR 0.84, 95%CI 0.77-0.98, P=0.029, Figure A) and FLAG-Ida (OS at 5yrs, 34% vs 23% for DA; RR 0.71, 95%CI 0.54-0.96, P=0.026, Figure B). Conclusion In older AML patients with evidence of residual disease following first induction, we saw a significant long-term survival benefit for intensified therapy with both DAC and FLAG-Ida in a randomized comparison with DA. This was despite early toxicity, observed particularly after FLAG-Ida. DAC intensification appeared better tolerated, delivered more patients to transplant and was associated with a greater conversion to MRD negativity.

Impact of Socioeconomic Disparities on Outcomes in Adults Undergoing Allogeneic Hematopoietic Cell Transplantation for Acute Myeloid Leukemia

Introduction: It is increasingly recognized that racial and socioeconomic disparities play an important prognostic role and contribute to differences in outcomes in adults receiving chemotherapy for acute myeloid leukemia (AML). Structural racism has also been implicated in limiting access to allogeneic hematopoietic cell transplantation (HCT). However, it is unclear to what degree racial and socioeconomic disparities impact post-HCT outcomes of patients with AML in contemporary practice. To address this uncertainty, we investigated the impact of socioeconomic, racial, and non-biologic disparities on outcomes in a large cohort of adults with AML undergoing allogeneic HCT while in first or second morphologic remission. Methods: We identified 1,004 adults with AML (2022 ICC criteria) who underwent allogeneic HCT between 5/2006 and 10/2021 at a single large university-affiliated cancer center. Data was collected on each patient's individual socioeconomic status (SES), including occupation, insurance type, and education attainment. Distance traveled, marital status, household size, country of birth, and religious affiliation were also recorded. Each occupation was classified by the International Socio-Economic Index (ISEI), a standard index of occupational status. Area-level SES was analyzed through the Area Deprivation Index (ADI), a validated measure of socioeconomic disadvantage which corresponds to U.S. census tract measurements. Collected HCT variables include the AML treatment-related mortality score (TRM), pre-HCT flow cytometric MRD status, HLA donor status, cytogenetic risk, conditioning regimen intensity, and incidence of severe acute and chronic graft-vs-host disease. Measured outcomes include non-relapse mortality (NRM), overall survival (OS), relapse, and relapse free survival (RFS). Cause-specific hazard models were used for univariate and multivariable regression analysis and C-statistics were calculated to quantify each model's ability to predict outcomes. Results: In univariate analysis, none of the socioeconomic or non-biologic factors were significantly associated with NRM, and all had poor predictive performance, with C-statistics not exceeding 0.53 for: marital status, larger household size (i.e., patients with children), distance traveled, ISEI, ADI, insurance status, educational attainment, or country of birth. TRM score (P<0.001), non-myeloablative conditioning (P<0.001), reduced intensity conditioning (P<0.001), CR2 (P=0.017) and marital status (P=0.014) were significantly associated with NRM in a multivariable model, but predictive performance of this model was only fair (C=0.69; Table 1). Marital status was only associated with NRM after multivariable adjustment but not on univariate evaluation, possibly because married patients were, on average, older (P<0.001), more likely to be male (P<0.001), and have higher occupational status/ISEI (P<0.001) and TRM scores (P<0.001), with age and sex as likely confounders (Table 2). African American patients (n=14) were found to have worse NRM in both univariate (P=0.036) and multivariate (P=0.024) models, consistent with previously identified racial/ethnic disparities in AML cohorts. Similar results were found for SES and non-biologic variables in regards to OS, relapse, and RFS. Notable exceptions after multivariable adjustment include: ADI was significantly associated with OS (P=0.036) and RFS (P=0.044) and marital status was not significantly associated with OS or relapse. Additional analyses demonstrated that ISEI and ADI were not associated with increased TRM or HLA donor status. Finally, distance traveled decreased in HCT recipients post-2013 (P<0.003), though the number of AML-related transplants remained unchanged. Conclusion: In this retrospective, single center analysis, socioeconomic and non-biologic factors had very limited impact on outcomes following allografting for adults with AML. While reassuring, patients able to undergo allogeneic HCT are highly selected (e.g. need for caregiver, insurance, etc.) possibly accounting for this finding, as could integrated, multidisciplinary cancer care networks and longitudinal care coordination post-HCT. Further research is needed to investigate disparities among HCT-eligible patients and improve access to HCT with a focus on reducing racial/ethnic disparities.

Extended Nutritional Monitoring in Patients Undergoing Intensive Chemotherapy for Acute Myeloid Leukemia

Background Fit patients (pts) with acute myeloid leukemia (AML) are conventionally administered repeated cycles of intensive chemotherapy, often followed by allogeneic hematopoietic stem cell transplant. AML pts need to be long hospitalized in a protected setting, they are often prescribed a neutropenic diet and chemotherapy-induced gastro-intestinal toxicity is common. As a result, malnutrition is frequently observed, it sensibly reduces the quality of life and has the potential to undermine eligibility for intensive treatment, increase treatment-related toxicity, and ultimately reduce survival. Aims Aim of this study was to systematically assess the nutritional status of fit pts undergoing treatment for AML and to explore early predictors and associations with known nutritional risk scores and relevant clinical outcomes. Methods Nutritional Risk Screening 2002 (NRS) score was calculated for each patient at time of diagnosis (a score of 3 or more is considered high). Then, nutritional monitoring included standard anthropometric measurements (body weight, BW; body mass index, BMI) and a bioelectrical impedance analysis (BIA) performed by a registered dietitian to assess fat-free mass, body cell mass (BCM, the metabolically active component of body mass), fat mass and the phase angle. Variations in nutritional parameters between admission and day 7 (end of CHT, called “dif7”) or between admission and day 14 (called “dif14”) were calculated and tested for correlation with variations of the same parameter at discharge from the same cycle (called “dif30”) or at discharge after the first consolidation (called “dif60”). Results Up to now, 26 pts with newly diagnosed AML (median age 55y, range 21-74) were prospectively monitored during a total of 61 cycles of intensive chemotherapy (35 induction cycles, 26 consolidation cycles). Median NRS score at enrolment was 3 (range 2-6). Median follow up for surviving pts is 300 days. We observed a significant reduction in fat-free mass and body cell mass during induction cycles. Similar trends, although not significant, were observed for consolidation cycles as well. These trends were observed irrespectively of baseline NRS, disease response, or whether admission was complicated by a fever lasting more or less than 7 days. A high NRS score was only associated with a greater fat mass loss between diagnosis and discharge after first consolidation (FM dif60), but the score failed to predict any meaningful nutritional parameter variation. For fat-free mass, body cell mass and the phase angle (but not for BW or BMI), dif7 correlated with dif30 for induction and consolidation cycles. For body cell mass and the phase angle, both dif7 and dif14 also correlated with dif60. Only variations in body cell mass at day 7 (BCM dif7) correlated with cumulative weight loss at discharge after the first consolidation cycle (BW dif60). Reduction in BW, BMI and fat mass at day 7, and of phase angle at day 14, were associated with extended length of stay for consolidation chemotherapy cycles only. Conclusions In this study, pts intensively treated for AML suffered a significant reduction in the metabolically active component of body mass during admission for induction chemotherapy and, cumulatively, during the first two treatment cycles. Bioelectrical impedance analysis performed as early as seven days from admission could already reveal the first signals of nutritional deterioration: body cell mass loss between day 0 and day 7 correlated with both cumulative body cell mass loss and cumulative body weight loss after two cycles of chemotherapy. Notably, a commonly used nutritional risk screening tool failed to predict the risk of malnutrition in our cohort of patients. “NUTRIAMO” is a prospective, observational trial currently starting at our institution, where pts intensively treated for AML are monitored via known nutritional assessment tools, new biochemical markers (e.g., prealbumin and retinol-binding protein) and microbiome analysis and variations. Our aim is to find more sensitive nutritional triggers to activate earlier and more effective support measures (e.g., oral nutritional supplements, diet variations, psychological support) and ultimately improve AML patients' quality of life and survival beyond the cure of their disease.

Virtual Reality-Assisted Exercise Therapy during Inpatient Treatment after Intensive Chemotherapy for Acute Myeloid Leukemia (AML) and after Autologous or Allogeneic Stem Cell Transplantation

Background and Objectives Medical advances in treatment of hematologic malignancies have led to improved survival. However, aggressive treatments come with the potential of significant side effects that can affect quality-adjusted life years. During treatment, physical activities are markedly reduced and immobility and psychologic burden, especially during long isolation processes, result in fatigue and decline of quality of life as well as loss of cognitive function. Physiotherapy and exercise therapy positively impact muscle strength, quality of life, cognitive functioning and fatigue, but sufficient implementation of training in the inpatient setting is often limited by shortage in human resources. The aim of this study was to assess the feasibility of a virtual reality (VR) based exercise program during inpatient stay of patients undergoing intensive treatment for hematologic malignancies, including autologous and allogeneic hematologic stem cell transplantation (HSCT). Method Patients aged 18 or above, admitted to the hematology ward for HSCT or intensive chemotherapy for acute leukemia were included. As this was a feasibility trial, there was no randomization. After consent, patients were asked to use the VR training device on a daily basis for the length of their stay, accompanied by medical personal. The training program consisted of customized VR-applications addressing movement, concentration and alertness as well as relaxation. An individual program was developed for every patient at the beginning of treatment and continuously readjusted according to individual needs and preferences. Patients who did not want to or were not able to use the VR device were asked to participate in the control group and received the standard-of-care treatment consisting of once daily physiotherapy. As objectives, quality of life, fatigue, strength and cognitive function were assessed once weekly until discharge as well as two weeks post discharge in both groups. The time of usage was recorded by the VR device. A structured interview was conducted after discharge to evaluate the patients' perspective on the intervention. Results Over a three-months period, a total of 10 patients were enrolled in the study, seven patients with intervention, three patients in the control group. The usage was feasible and well tolerated. No unpleasant side effects such as dizziness, nausea or fatigue were reported. Mean time of usage varied between patients (132.6±68.6 minutes, min 12.4, max 463.5 minutes) on 31±28.2% of hospitalization days. Patients in the intervention group achieved a higher overall score in EORTC QLQ-C30 after discharge (s). Moreover, the use of VR was associated with a trend towards improved mean symptom burden (60 vs 43.3 pts), cognitive function (83.3 vs. 16.7pts) and physical strength (63.3 vs 26.7pts) post discharge (significance was not calculated due to the small number of cases). VR occupation time was markedly affected by age and general condition during treatment. The patients perception of the intervention was positive. Conclusions The results show that the use of a VR based exercise program during inpatient stay of patients receiving intensive treatment for hematologic malignancies is feasible and safe, and can improve QoL. Because of the small number of subjects and distinctive differences in time of usage we can only recognize a trend towards positive effects so far. In view of these promising results a larger prospective, randomized trial has been designed.

FLT3 Inhibitors in Combination with FLAG-IDA in Relapsed or Refractory Acute Myeloid Leukemia

1. Introduction The addition of a FLT3 inhibitor improves overall survival in combination with front-line intensive chemotherapy in acute myeloid leukemia (AML). In the ADMIRAL trial, gilteritinib - a second-generation, type I FLT3 inhibitor - improved survival in relapsed or refractory AML compared to intensive chemotherapy. However, it is unknown whether the combination of a FLT3 inhibitor and intensive chemotherapy improves survival in the relapsed or refractory setting compared with intensive chemotherapy alone or intensive chemotherapy with venetoclax in FLT3 mut AML. 2. Methods We analyzed 27 patients with FLT3 mut AML treated with FLAG-IDA for relapsed or refractory disease from January 1, 2013 to April 18, 2023 at VCU Massey Comprehensive Cancer Center. Baseline disease characteristics were obtained, including molecular profiling either through PCR, NGS, or both, alongside cytogenetic risk, doses of induction regimens, response, and survival. We separated patients that underwent treatment with FLAG-IDA and a FLT3 inhibitor (gilteritinib, midostaurin, or sorafenib), venetoclax, or FLAG-IDA alone. Measurable residual disease (MRD) assays were PCR-based when available; otherwise, MRD was assessed through multiparameter flow cytometry. We used the D'Agostino & Pearson method for normality testing and the Kruskal-Wallis test for between-group comparisons. We applied the Bonferroni correction if multiple comparisons were made. We analyzed survival by the Kaplan-Meier method with significance determined by the log-rank test. The event for calculating the overall survival (OS) was the date of death. Patients were otherwise censored at the date of last contact. 3. Results All 27 patients treated with FLAG-IDA harbored mutations in FLT3-ITD (70.3%) or FLT3-TKD (29.6%). Twelve (44.4%) patients received FLT3 inhibitors with FLAG-IDA: eight (66.7%) with midostaurin, three (25.0%) with gilteritinib, and one (8.3%) with sorafenib. Five (41.6%) patients received a FLT3 inhibitor (FLT3i) for previously untreated disease, then subsequently received a FLT3i at disease progression. Ten (37.0%) patients received FLAG-IDA without a FLT3i, and five (18.5%) received FLAG-IDA and venetoclax. The median FLT3 variant allele frequency was 33.96% (95% CI, 5.1-63.9) in the FLT3i cohort, 18.0% (95% CI, 8.0-27.0) in the FLAG-IDA cohort, and 5.0% (95% CI, 3.0-29.0) in the venetoclax cohort. The median prior lines of therapy were as follows: three for the FLT3i cohort, two for the FLAG-IDA cohort, and three for the venetoclax cohort (p = 0.137). There was no difference in the achievement of CRc between the FLT3i and FLAG-IDA groups (27.3% vs 33.3%, p > 0.999) or between the FLT3i and venetoclax groups (27.3% vs 50.0%, p = 0.560). The proportion of responders that achieved MRD negativity was nonsignificantly higher in the FLT3i cohort (75.0% vs 20.0%, p = 0.206). The median overall survival nonsignificantly favored the FLT3i cohort compared to the FLAG-IDA cohort (7.7 months vs 4.1 months, p = 0.992) and the venetoclax cohort (7.7 months vs 6.3 months, p = 0.902). 4. Discussion The addition of a FLT3 inhibitor resulted in nonsignificantly higher rates of MRD negativity and prolonged overall survival when compared to FLAG-IDA alone or FLAG-IDA and venetoclax. The optimal combination regimen for relapsed or refractory FLT3 mut AML is unknown, but likely should include a FLT3 inhibitor. The limitations of our study include its retrospective nature; subsequent FLT3 inhibitor combinations or maintenance strategies may have provided a survival benefit the FLT3i cohort. Therefore, prospective clinical trial designs are needed to further confirm these findings.

Association between BMI and Survival in Adolescents and Young Adults (AYA) with Acute Myeloid Leukemia Treated with Intensive Chemotherapy

Introduction: Obesity is linked to a higher incidence of acute myeloid leukemia (AML) in older adults as well as B-cell acute lymphoblastic leukemia in children and adolescents and young adults (AYA). To date, however, the relationship between weight and clinical outcomes in AYA patients (pts) diagnosed with AML has not been clearly established. We hypothesized that obesity reflected by higher body mass index (BMI) would confer worse prognosis in AYA pts treated with intensive chemotherapy and/or allogeneic stem cell transplant (SCT) for AML. Methods: We conducted a single institute retrospective chart review of AYA patients aged 18 to 39 years diagnosed with AML between Jan 2006 and Oct 2022. All patients received intensive chemotherapy with cytarabine- and anthracycline-based induction and consolidation chemotherapy followed in some cases by SCT. BMI was calculated based on height and weight on the date of AML diagnosis. Additional information including European Leukemia Net (ELN) 2022 risk classification, therapy response (complete remission (CR), CR with incomplete count recovery [CRi]), receipt of SCT, relapsed disease, event-free (EFS), overall survival (OS) and percentage of pts alive at 2- and 5-years after diagnosis were collected. All data was de-identified and procured on an IRB-approved protocol. Results: Seventy-six AYA patients were identified. Median age was 25.2 (range 18-39) years. 39 (51%) were female. The majority (65, 86%) were Caucasian. Per ELN 2022 risk classification, 24 (32%) had favorable, 36 (47%) had intermediate, and 16 (21%) had adverse risk disease. The CR rates based on ELN 2022 risk classification were 86%, 72% and 50%, respectively. Median OS for all pts was 791 days and per risk group was 1379, 569, and 595 days, respectively. Pts were then categorized per initial BMI into 4 categories. The majority of pts (44, 58%) had above average BMI (≥ 25), with 21 (28%) considered overweight with BMI 25-29.9 and 23 (30%) obese defined as BMI >30. Only 3 pts (4%) were underweight with BMI <18.5 (Table 1). Of note, 43% of obese pts had ELN favorable risk vs 33% of overweight pts and 24% of normal weight pts. Overall response rates in each BMI category were similar, ranging from 96-100% except in overweight pts where only 6 of 21 pts (29%) obtained CR. Relapse occurred in approximately one third (29-35%) of pts in the three highest BMI categories. Two thirds of all pts with BMI ≥18.5 underwent SCT. Excluding underweight pts due to small numbers (n=3), there was a trend to decreased survival in pts with BMI ≥18.5. Median overall survival among normal, overweight, and obese pts was 1403, 1295, and 777 days, respectively, with a significant difference between healthy and obese pts (p-value 0.0274 by log rank test). The percentage of pts alive after 5 years was 41%, 29%, and 17%, respectively (Table 2). Conclusion: Our real-world single-institute retrospective analysis suggests that AYA pts aged 18-39 yrs old diagnosed with AML and with higher BMI have decreased overall survival following intensive chemotherapy and/or allogeneic transplant. Obese patients with the highest BMI (>30) had a markedly shorter overall survival (median 777 days) and lower percentage of pts (17%) alive after five years following therapy than AYA AML pts with normal BMI (median 1403 days, 41% 5-year survival). This was despite over 40% of obese pts having favorable ELN risk. Potential reasons for this include biological heterogeneity in BMI cohorts, chemotherapy dosing, weight-related medical co-morbidities (i.e. cardiovascular disease) and/or transplant-related complications leading to shorter survival. Additional analyses to rule out the contribution of these and other factors and to confirm these results in a larger cohort are ongoing.

Comparative Effectiveness of Reinduction Approaches for Pediatric Relapsed Acute Myeloid Leukemia

Introduction: Intensive frontline chemotherapy achieves initial remission rates above 80% in pediatric acute myeloid leukemia (AML), however, approximately half of patients relapse, and overall survival (OS) after relapse is poor. There is a paucity of comparative effectiveness data on salvage regimens to inform selection of optimal post-relapse therapy. The objective of this analysis was to compare outcomes following relapse by prevalent reinduction regimens in a multi-center real-world dataset. Methods: Patients 18 years and younger who had received frontline chemotherapy for AML between 2011-2019 at 12 pediatric institutions were eligible for inclusion. Trained personnel completed manual chart abstraction to obtain demographics, diagnosis, treatment, and outcome information. The analysis included patients who achieved morphologic remission and then experienced disease relapse; patients with primary refractory AML and those who pursued palliative therapy only after relapse were excluded. Prevalent reinduction regimens were classified as (1) intensive without anthracycline [e.g. fludarabine/cytarabine and high-dose cytarabine-containing regimens], (2) intensive with anthracycline (e.g. CPX-351, mitoxantrone/cytarabine and cytarabine/daunorubicin/etoposide), and (3) non-intensive (including azacytidine or decitabine-based regimens). Primary outcomes were OS after relapse and end reinduction disease response defined by morphologic remission (<5% blasts) and measurable residual disease (MRD)-negative remission (<0.1% blasts). Covariate distributions were compared by reinduction regimen using chi-square tests. Survival analyses used Kaplan-Meier methods and multivariable cox proportional hazards models. End induction response was evaluated using logistic regression. Adjustment was made for covariates found to both differ by reinduction regimen and be associated with outcome, regardless of statistical significance. Results: Of 530 patients, 157 (29.6%) experienced a relapse at a median of 9.7 months (IQR 6.5-16.3) after initial diagnosis. Median post-relapse follow-up was 2.2 years (IQR 1.1-3.2). One- and 2-year OS rates from relapse were 44.9 ± 4.1% and 38.6 ± 4.1%, respectively. Of 157 patients with relapse, 129 from 9 institutions had available information on post-relapse treatment and pursued reinduction with curative intent. Patients were 48.8% female, 27.1% Hispanic, 14.7% non-Hispanic Black and had a median age of 7.1 years (IQR 2.70-14.2) at relapse. Most patients (89.2%) relapsed after completion of frontline therapy, and 24% had undergone hematopoietic cell transplantation (HCT) in first clinical remission. Reinduction regimens were as follows: 79 (61.2%) received intensive reinduction without anthracycline, 34 (26.4%) received intensive reinduction with anthracycline and 16 (12.4%) received non-intensive reinduction. Patients with a non-intensive reinduction were more likely to have relapsed within one year of initial diagnosis (50% versus 34%, p = 0.23) and undergone transplant prior to relapse (75.0% versus 16.8%, p < 0.001). Covariates were balanced across intensive induction regimens. One-year OS was 50.3 ± 4.6%, with 63 (40.1%) achieving morphologic remission and 40 (31.0%) achieving an MRD-negativity after first reinduction cycle. Seventy-three patients (56.9%) underwent HCT after relapse; 11 (15.1%) received a second transplant. OS curves and adjusted outcome comparisons by reinduction regimen are shown in the Figure and Table. One-year OS was 51.1 ± 5.8%, 60.2 ± 9.0% and 26.7 ± 11.4% for intensive therapy without anthracycline, with anthracycline and non-intensive, respectively. However, after adjustment hazard ratios (HRs) were not statistically significant [HR = 0.85 (p = 0.65) and 1.77 (p = 0.23) for intensive with anthracycline and non-intensive, compared to non-intensive without anthracycline, respectively]. Conclusions: After controlling for patient, disease and treatment characteristics, we did not identify a significant difference in remission rates or OS by reinduction approaches for pediatric relapsed AML. Although anthracycline-based reinduction did not improve OS, adjusted point estimates suggest that anthracyclines may improve end reinduction disease response. Ongoing cohort expansion will enable comparative effectiveness analyses of specific reinduction regimens.

Selinexor in Combination with Hypomethylating Agent (HMA) in Patients with Refractory/Relapsed Acute Myeloid Leukemia (AML) Previously Exposed to Venetoclax: A Retrospective Study

Background Acute myeloid leukemia (AML) is a heterogeneous hematologic tumor with varied clinical manifestations. Venetoclax combination regimens have shown promising results as a first-line treatment for AML. However, for patients who fail venetoclax treatment, the prognosis remains poor, necessitating the exploration of new therapeutic approaches. Selinexor, a selective inhibitor of XPO1, has shown potential as a therapeutic strategy to overcome resistance to conventional chemotherapy for AML. Here, we report the safety and efficacy data from a real-world study of selinexor + HMA in patients with refractory/relapsed (R/R) AML previously exposed to venetoclax. Methods We conducted a monocentric retrospective analysis on adult patients with unfit R/R AML or those with comorbidities preventing the use of intensive induction chemotherapy. The patients received selinexor-based combinations between May 2021 and December 2022. AML genetic risk stratification and response criteria were assessed according to the 2022 European Leukemia Net (ELN) consensus. The selinexor + HMA regimen consisted of selinexor 40 mg twice weekly for 3 weeks orally, and either decitabine (DAC, 10 mg/dfor 7-10 days intravenously) or azacytidine (AZA, 75 mg/m 2/d for 7 days subcutaneously, halved for patients over 60 years). Supportive treatments and dose adjustments were administered based on individual clinical indications. Some patients underwent allogeneic hematopoietic stem-cell transplantation. Results A total of 12 patients with R/R AML treated with selinexor-based combinations were considered in this study, including 7 patients with refractory AML and 5 patients with relapsed AML (one with post-transplant recurrence). The median age of the patients was 36 years (range 18-68 years). All patients had intermediate or adverse ELN genetic risk. All patients had previously received venetoclax-based combinations, and 58% (7/12) had been treated with HMAs. The overall response rate (ORR) was 66.7% (8/12) with a combined CR rate (CRc) of 50% (6/12). Among the 6 patients with CRc, 3 (50%) achieved negative minimal residual disease (MRD,≤1*10 -3). CRc was 42.9% (3/7) in patients previously exposed to HMA-based therapy and 100% in patients without exposure history. The most common grade 3 or 4 adverse events were neutropenia (83.3%) and thrombocytopenia (58%), with the median recovery time of 14 (8-21) and 16 (8-24) days, respectively. Common non-hematologic toxicities included infection (66.7%) and gastrointestinal reactions (66.7%). As of Jun 20, 2023, with a median follow-up of 11.3 months (range 0.7-19.5 months), 50% (6/12) of the patients died due to disease progression or severe infections. 66.7% (8/12) of the patients received transplants after achieving remission. The median overall survival (OS) was significantly longer in the transplantation group compared to the non-transplantation group (p=0.009) (Figure.1a). Patients without previous HMA exposure seemed to have a better efficacy benefit from the X+HMA combination regimen, although the difference was not statistically significant due to the llimited sample size (Figure.1b). Conclusion The real-life study demonstrated that the combination of selinexor and HMAs is a viable and safe option for patients with unfit R/R AML who were previously exposed to venetoclax. X+HMA salvage therapy followed by transplantation showed durable survival benefits in R/R AML patients, especially those without prior HMA exposure, suggesting a potential efficacy advantage.

Prospective MRI and Neurocognitive Assessment of “Chemobrain” in Acute Myeloid Leukaemia: The Mineral Study

CONCLUSIONS “Chemobrain” is commonly reported by patients treated for Acute Myeloid Leukaemia (AML), potentially attributable to chemotherapy or iron overload. We aimed to determine whether “chemobrain” could be objectively detected in AML patients. We performed a prospective, observational, longitudinal cohort study in adults commencing chemotherapy for AML, powered to capture a potential 25% incidence of “chemobrain.” Participants underwent neurocognitive assessment (NCA) and brain magnetic resonance imaging (MRI), including iron quantitative susceptibility mapping (QSM), as a biomarker of neuro-inflammation, at three timepoints: pre-treatment (T1), end of treatment (T2), and 6 months later (T3). Longitudinal changes of minimum 1.64 SD were considered significant. The primary outcome was change in NCA score between T1-T2, with secondary correlation analyses between NCA, MRI, QSM and clinical data. This study was funded by a RBWH Foundation 2018 Diamond Care Grant. Between January 2019 and June 2021, 20 patients were enrolled; of these, 15 and 10 remained alive/enrolled for evaluation at T2 and T3 respectively. Overall NCA scores for the cohort between T1-T2 were similar; however, four (27%) participants performed significantly worse (-1.64SD) in Language or Verbal Memory, with three returning to baseline at T3. Objective NCA score did not correlate with subjective symptoms, and quality of life and physical fatigue improved T1-T2. Cohort brain volumes were similar T1-T2; however, correlation analysis identified interesting potential associations between worse Language performance and volume loss in grey matter (GM; p=0.021) and Wernicke's area (p=0.02), and suggested increased iron susceptibility in frontal lobe (p=0.041) and possibly cortical GM (p=0.055). Despite patient-reported symptoms, objective neurological toxicity appears uncommon in AML patients, and those with measurable impairment appear to subsequently return to baseline.

A Single Center Retrospective Analysis Comparing the Outcomes of Induction Therapy between 7+3 and FLAG-IDA/Venetoclax in Newly Diagnosed Patients with Acute Myeloid Leukemia

Introduction Induction chemotherapy (IC) in acute myeloid leukemia (AML) in younger and fit patients has historically combined an anthracycline (ie, daunorubicin or idarubicin) with the antimetabolite cytarabine, which has been termed the 7 + 3 regimen. Response rates with this current standard approach show complete response rates of 70-80%, however 30-40% still eventually relapse. Recently, the MD-Anderson group published a phase II study in which the drug venetoclax was added to the standard anthracycline/cytarabine induction regimen of FLAG-IDA. Results from this study showed an impressive 96% response rate for newly diagnosed (ND) AML patients. Based on these results we began to adopt this approach for our patients. We have induced 21 patients with this approach at our institution and have had comparable results. No study has compared outcomes between this approach and that of standard 7 +3 in regards to response rates. Based on our improved outcomes we compared outcomes between these two approaches in our patient population by doing a retrospective chart based review on all patients that received cytotoxic induction treatment for ND-AML between 2000-2023. Methods Patients between 2020-2023 that were treated with induction cytotoxic chemotherapy for AML, based on WHO 2016 criteria, were retrospectively reviewed. Patients either received 7+3 or 7+3 plus midostaurin if they were FLT3+ in one arm or FLAG-IDA/Venetoclax. Patients received FLAG-IDA/Venetoclax regardless of FLT3+ status or risk of disease. Patients with extra medullary disease were excluded from this review as well as patients that received an IDH1 or 2 inhibitors in combination with 7 +3. Results Overall 39 patients were included in this study, 20 patients in the FLAG-IDA/Venetoclax arm and 19 patients in the 7/3 arm. In patients which response was able to be evaluated patients in the FLAG-IDA/Venetoclax cohort had a 100% overall response rate with a 95% (N = 19/20) complete response rate. Patients in the 7/3 cohort the complete remission rates were 66% (N = 12/16) with 3 of the patients achieving a complete remission with re-induction. Sixty-day morality rate was 5% (N = 1/20) in patients receiving FLAG-IDA/Venetoclax compared to 16% (N = 3/19). In terms of neutrophil recovery and toxicity results were comparable in both arms, with the average day to cell recovery being the similar in both groups. Conclusions FLAG-IDA/Venetoclax compared to standard 7/3 +/- FLT3 directed therapy in our patient population resulted in improved response rates and decreased 60-day mortality. Our results are similar to previously published reports in patents with ND-AML. Toxicity profiles were similar with the clear benefit of decreased early morality are increased response rates.

Frail and Pre-Frail Older Adults with Acute Myeloid Leukemia Have Inferior Survival Due to Higher Rates of Disease-Related Deaths

Introduction: The intensity of initial remission-inducing therapy for patients with newly diagnosed acute myeloid leukemia (AML) may be high (anthracycline and cytarabine-based), intermediate (venetoclax combinations), or low (single hypomethylating agent or targeted therapy). In older adults, it is important to consider “fitness” when selecting initial therapy. Current methods to determine “fitness” in AML include subjective measures such as physician assessment (“clinician gestalt, CG”) semi-subjective measures such Eastern Cooperative Oncology Group (ECOG) or Karnofsky performance status (KPS), and those based on clinical comorbidity data like the hematopoietic cell transplantation-comorbidity index (HCT-CI). Geriatric assessments in older adults with cancer may improve therapy selection and decision-making, but whether unfit patients have better outcomes with lower intensity compared to higher intensity therapies is unknown. Freid's Frailty Phenotype (FP) combines subjective (self-reported exhaustion, weight loss >5%, activity level) and objective (4-meter walk speed and grip strength) measures to categorize patients into fit, pre-frail, and frail. We hypothesized that being frail by FP is associated with higher overall mortality (OM) and inferior overall survival (OS) and may inform decision-making for older adults. Methods: Eighty-fivepatients 60 years or older admitted to the Hospital of the University of Pennsylvania at the time of AML diagnosis or electively admitted for AML chemotherapy initiation were prospectively enrolled from September, 2018 to May, 2023 on an IRB approved study. FP, HCT-CI, KPS, ECOG, gait speed, and recorded CG (fit or unfit) were performed prior to initiation of disease-directed therapy. Results: Themedian age of the cohort was 71 (range60-91). Patients in our cohort had high-risk disease features: 64% were adverse risk by European LeukemiaNet (ELN) 2017 with 73% of patients harboring mutations associated with clonal hematopoiesis of indeterminate potential (CHIP) (Table 1). 39% of patients received IC, 52% received HMA/ven, 6% received HMA alone or targeted therapy, and 2% received best supportive care. By FP, 18% of patients were fit, 38% were pre-frail, and 45% were frail. Higher ECOG, KPS, CG, and HCT-CI were associated with frail phenotypes (Table 1). For the entire population, 60-day and 100-day OM rates were 18% and 33%, respectively. For fit, pre-frail, and frail patients 60-day OM was 7%, 13%, and 24% and 100-day OM was 13%, 22%, and 42%, respectively. Two-year OS was 65% for patients aged 60-69 years old and 15% for patients ≥70 years old (p=0.002). FP was significantly associated with OS (Figure 1; p=0.0474): 2-year OS was 57%, 42%, and 21% in fit, pre-frail, and frail patients, respectively. Of the individual components of FP, self-reported exhaustion and slower gait speed were both associated with inferior OS (p=0.0015 and p=0.0005). Neither activity level, (p=.0864), weight loss (p=0.1988), or grip strength (p= 0.7136) were associated with OS. Of the total population 19% went on to hematopoietic cell transplant (HCT) with 8% of frail patients receiving HCT compared to 27% of fit and 28% of pre-frail patients. ECOG, HCT-CI, CG, and gait speed ≤8 meters/sec were all significantly associated with OS, but KPS was not. The 6-month OS for frail patients receiving IC was 75% compared with 49.7% for those receiving HMA/Ven, although not significant due to small sample size. Cause of death was leukemia-related for 40% of fit patients, 76% of pre-frail patients, 77% of frail patients. Conclusions: FP was associated with a doubling of early mortality and inferior 2-year OS. Pre-frail and frail patients had increased disease-related deaths. This work supports that most geriatric assessments, including FP and clinician intuition, can be utilized to risk-stratify newly diagnosed older adults with AML. Future work is needed to evaluate whether we can integrate geriatric assessments, such as individual components of FP or gait speed, with molecular features to improve risk stratification of older adults with AML. Given frailty's association with disease-related deaths, further study is warranted to determine whether this is due to adverse disease biology or whether frail patients are undertreated.

A Necroptosis Inhibitor Functions As a Ferroptosis Inducer in Drug-Resistant Myeloid Malignancies

Introduction: Acute myeloid leukemia (AML) is associated with poor prognosis, especially in elderly patients unfit for intensive chemotherapy. AML chemotherapy agents, including venetoclax, a BH3-mimetic, are designed to induce cell death through apoptosis. Unfortunately, AML cells eventually develop a resistance to BCL-2-dependent apoptosis which causes clinical disease recurrence. Alternative cell death pathways like ferroptosis and necroptosis are lytic forms of cell death mediated by plasma membrane lipid oxidation or MLKL phosphorylation (p-MLKL), respectively, both of which disrupt plasma membrane integrity. Because apoptosis and ferroptosis involve different molecular pathways, ferroptosis-inducing therapies provide an opportunity to overcome therapy resistance in AML patients. Here, we show how necroptosis inhibitor targeting basal necroptosis signal selectively induces ferroptosis in venetoclax-resistant AML cells causing cell death. Methods: We established venetoclax-resistant myeloid cell lines by exposing cell lines to increasing doses of venetoclax. We evaluated resistance to venetoclax-induced apoptosis by measuring IC50 after Annexin-V/PI staining. We screened venetoclax-resistant myeloid cell lines and primary AML cells (n=77) for basal activation of necroptosis by pMLKL or phosphorylated RIP3 (pRIP3) western blotting. Xenotransplantation was performed to evaluate the bone marrow engraftment potentials of basal activated necroptosis primary AMLs. Necrosome inhibitor (Zharp-99) was tested to estimate IC50 for cell death induction in myeloid cell lines after Annexin-V/PI staining. Ferroptosis inhibitors (ferrostatin-1 and lipoxstatin-1) and apoptosis inhibitor (zVAD-FMK) were used to determine which death pathway was induced by necroptosis inhibitors in AML. Results: We established venetoclax-resistant myeloid cell lines (THP1-VR and HL60-VR), which showed a significant shift in IC50 for venetoclax-induced apoptosis compared to parent cell lines. Venetoclax-resistant cell lines acquired an upregulation of known anti-apoptotic proteins; BCL-2, BCL-XL, and MCL-1. Venetoclax-resistant cell lines upregulated pRIP3 signal, a known necroptosis driver, by western blot. Necrosome screening of primary AML samples revealed 73 AMLs (94%) showed basal necroptosis signal confirmed by pMLKL with heterogeneous intensities (Figure. A). Xenotransplantation confirmed engraftment of basal necroptosis-activated primary AMLs is achievable and with retention of necroptosis signal at engraftment. The basal necroptosis signal in venetoclax-resistant cell lines and primary AML samples drove us to evaluate necroptosis inhibitor Zharp-99 (RIP3K inhibitor) IC50 for venetoclax-resistant cell lines. Compared to parent cell lines, venetoclax-resistant cell lines became susceptible to cell death by necrosome inhibition. Surprisingly, the cell death induced by Zharp-99 was not from apoptosis but through ferroptosis, confirmed by the venetoclax-resistant myeloid cells being rescued from cell death by ferroptosis inhibitor (ferrostatin-1 and lipoxstatin-1) (Figure B). Conclusion: Basal activation of necrosome is observed in venetoclax-resistant myeloid cell lines and primary AML patient samples. We found necroptosis inhibitor Zharp-99 promoted cell death in necrosome-activated venetoclax-resistant cell lines. Our data suggest necroptosis inhibition targeting RIP3K activity has a novel function of inducing ferroptosis in myeloid malignancies resistant to apoptosis. RIP3K inhibitor, as a novel function of ferroptosis inducer in apoptosis-resistant myeloid cell lines, opens a new therapy opportunity to treat apoptosis resistance in AML patients. We plan to investigate in vivo effects of necrosome inhibitors using our xenotransplant model.

Folate-Appended Hydroxypropyl-β-Cyclodextrin Induces Autophagic Cell Death in Acute Myeloid Leukemia Cells

Acute myeloid leukemia (AML) is a heterogenous myeloid neoplasm that remains challenging to treat. Because intensive conventional chemotherapy reduces survival rates in elderly patients, drugs with lower toxicity and fewer side effects are needed urgently. 2-Hydroxypropyl-β-cyclodextrin (HP-β-CyD) is used clinically as a pharmaceutical excipient for poorly water-soluble drugs. Previously, we showed that HP-β-CyD exerts antitumor activity by disrupting cholesterol homeostasis. Recently, we developed folate-conjugated HP-β-CyD (FA-HP-β-CyD) and demonstrated its potential as a new antitumor agent that induces not only apoptosis, but also autophagic cell death; however, we do not know whether FA-HP-β-CyD exerts these effects against AML. Here, we investigated the effects of FA-HP-β-CyD on folate receptor (FR)-expressing AML cells. We found that the cytotoxic activity of FA-HP-β-CyD against AML cells was stronger than that of HP-β-CyD. Also, FA-HP-CyD induced the formation of autophagosomes in AML cell lines. FA-HP-β-CyD increased the inhibitory effects of cytarabine and a BCL-2-selective inhibitor, Venetoclax, which are commonly used treat elderly AML patients. Notably, FA-HP-β-CyD suppressed the proliferation of AML cells in BALB/c nude recombinase-activating gene-2 (Rag-2)/Janus kinase 3 (Jak3) double-deficient mice with AML. These results suggest that FA-HP-β-CyD acts as a potent anticancer agent for AML chemotherapy by regulating autophagy.

Modeling early treatment response in AML from cell-free tumor DNA

Monitoring disease response after intensive chemotherapy for acute myeloid leukemia (AML) currently requires invasive bone marrow biopsies, imposing a significant burden on patients. In contrast, cell-free tumor DNA (ctDNA) in peripheral blood, carrying tumor-specific mutations, offers a less-invasive assessment of residual disease. However, the relationship between ctDNA levels and bone marrow blast kinetics remains unclear. We explored this in 10 AML patients with NPM1 and IDH2 mutations undergoing initial chemotherapy. Comparison of mathematical mixed-effect models showed that (1) inclusion of blast cell death in the bone marrow, (2) transition of ctDNA to peripheral blood, and (3) ctDNA decay in peripheral blood describes kinetics of blast cells and ctDNA best. The fitted model allows prediction of residual bone marrow blast content from ctDNA, and its scaling factor, representing clonal heterogeneity, correlates with relapse risk. Our study provides precise insights into blast and ctDNA kinetics, offering novel avenues for AML disease monitoring.

Measurable residual disease conversion rate with consolidation chemotherapy in acute myeloid leukemia

The rate of MRD clearance in AML with standard consolidation chemotherapy is not well defined. A multi-institution retrospective analysis was performed on 107 consecutively treated AML patients in morphologic complete remission with detectable MRD post-induction therapy who received standard chemotherapy consolidation. In response to standard intermediate/high-dose cytarabine consolidation therapy, 26 of 60 patients (43.3%) with MRD threshold of detection of at least 0.1% converted to MRD-negative status (undetectable with assay used), and 6 of 47 patients (12.8%) with MRD threshold of detection > 0.1% converted to MRD-negative status. Multivariable logistic regression for patients with MRD threshold of detection of at least 0.1% showed that, when controlling for age, ELN risk category, dose of cytarabine, and use of a combination agent, treatment with 1 cycle of consolidation cytarabine versus ≥2 cycles decreased the odds of conversion of AML to MRD-negative (OR = 0.24, 95% CI 0.07–0.85, p = 0.03).

Artesunate reverses cytarabine resistance in acute myeloid leukemia by blocking the JAK/STAT3 signaling

ABSTRACTObjectivesAlthough cytarabine (AraC) has greatly contributed to improving the prognosis of patients with acute myeloid leukemia (AML), many patients developed drug resistance and eventually succumbed to AML. Thus, resistance to AraC is a major obstacle to improve the efficacy of chemotherapy in AML. Hence, this study aimed to demonstrate that artesunate (ART) can reliably induce cell death in vitro and block AraC resistance.MethodsAML cell lines resistant to AraC were first constructed by repeated dosing for 5 months. Further, we analyzed whether ART intervention affected the sensitivity of AraC-resistant cells to AraC by cell function experiments, mainly including CCK-8 to assess cell viability, flow cytometry to examine apoptosis, and Western blotting to measure the Janus kinase (JAK)/signal transducers and activators of transcription 3 (STAT3) pathway protein expression. Furthermore, whether JAK/STAT3 pathway knockdown has a blocking effect on the efficacy of ART was also assessed.ResultsCo-treatment of ART and AraC increased the sensitivity of AML cells to AraC. Also, it effectively reversed the resistance of AML cells to AraC that is shown by the significantly reduced proliferation and increased apoptosis rates. ART intervention suppressed the activation of the JAK/STAT3 signaling pathway in AraC-resistant AML cells, suggesting that the function of ART in reversing AraC resistance is indeed dependent on the JAK/STAT3 signaling pathway.ConclusionsIn summary, ART enhanced the sensitivity of AML/AraC-resistant cells to AraC by modulating the JAK/STAT3 pathway.

Distinct N7-methylguanosine profiles of circular RNAs in drug-resistant acute myeloid leukemia

Post-transcriptional methylation modifications, such as the N7-methylguanosine (m7G) modification, are increasingly acknowledged for their role in the development and resistance to chemotherapy in acute myeloid leukemia (AML). This study employed MeRIP-seq technology to investigate the m7G sites within circular RNAs (circRNAs) derived from human AML cells and drug-resistant AML cells, in order to identify these sites more comprehensively. In addition, a detailed analysis of the relationship between m7G and drug-resistant AML was conducted. The bioinformatics analysis was utilized to predict the functions of specific methylated transcripts. The findings revealed a significant difference in m7G level between AML cells and drug-resistant AML cells, suggesting a potentially critical role of m7G in circRNAs in drug-resistant AML development. The methylation of M7G could affect the circRNA-miRNA-mRNA co-expression during the development of AML resistance, which could further influence the regulation of resistance-associated target genes in AML. Furthermore, gene ontology analysis indicated that the distinct distribution pattern of circRNAs with m7G methylation in drug-resistant AML cells was correlated with metabolism-related pathways. These results suggested a potential association between drug-resistant AML and m7G methylation of circRNAs. Moreover, the results revealed a novel role of m7G RNA methylation in circRNAs in the progression of AML chemoresistance.