Favorable Risk Acute Myeloid Leukemia Research Articles

Trends in Allogeneic Transplantation for Favorable Risk Acute Myeloid Leukemia in First Complete Remission: A Longitudinal Study of > 15 Years from the ALWP/EBMT

Trends in Allogeneic Transplantation for Favorable Risk Acute Myeloid Leukemia in First Complete Remission: A Longitudinal Study of > 15 Years from the ALWP/EBMT

Proteogenomic analysis reveals cytoplasmic sequestration of RUNX1 by the acute myeloid leukemia-initiating CBFB::MYH11 oncofusion protein.

Several canonical translocations produce oncofusion genes that can initiate acute myeloid leukemia (AML). Although each translocation is associated with unique features, the mechanisms responsible remain unclear. While proteins interacting with each oncofusion are known to be relevant for how they act, these interactions have not yet been systematically defined. To address this issue in an unbiased fashion, we fused a promiscuous biotin ligase (TurboID) in-frame with 3 favorable-risk AML oncofusion cDNAs (PML::RARA, RUNX1::RUNX1T1, and CBFB::MYH11) and identified their interacting proteins in primary murine hematopoietic cells. The PML::RARA- and RUNX1::RUNX1T1-TurboID fusion proteins labeled common and unique nuclear repressor complexes, implying their nuclear localization. However, CBFB::MYH11-TurboID-interacting proteins were largely cytoplasmic, probably because of an interaction of the MYH11 domain with several cytoplasmic myosin-related proteins. Using a variety of methods, we showed that the CBFB domain of CBFB::MYH11 sequesters RUNX1 in cytoplasmic aggregates; these findings were confirmed in primary human AML cells. Paradoxically, CBFB::MYH11 expression was associated with increased RUNX1/2 expression, suggesting the presence of a sensor for reduced functional RUNX1 protein, and a feedback loop that may attempt to compensate by increasing RUNX1/2 transcription. These findings may have broad implications for AML pathogenesis.

Hyperleukocytosis Does Not Present a Worse Prognosis in Acute Myeloid Leukemia (Non-APL) with Favorable Risk According to ELN-2022 Criteria: A Retrospective Study

Introduction: Acute myeloid leukemia (AML) with hyperleukocytosis, characterized by a white blood cell count ≥100,000/µL, is usually considered a subtype associated with poor prognosis. For AML patients with hyperleukocytosis, more aggressive treatment approaches, such as allogeneic hematopoietic stem cell transplantation (allo-HSCT), are commonly considered. However, when favorable-risk AML accompanies hyperleukocytosis, it is unclear whether the risk level needs to be redefined. There is also no universally accepted treatment strategy for this subtype. We conducted a retrospective, single-center study to investigate the impact of hyperleukocytosis on the response and prognosis of favorable-risk AML according to ELN-2022 risk classification. Method: We retrospectively enrolled 217 favorable-risk AML patients, excluding acute promyelocytic leukemia (APL), treated at Zhejiang University School of Medicine's First Affiliated Hospital from October 1st, 2021, to April 30th, 2023. Some of them have been treated in other hospitals. The diagnosis, risk classification, and response evaluation were determined according to ELN-2022 criteria. Patients were divided into two groups: the hyperleukocytosis group (white blood cell count ≥100,000/µL) and the non-hyperleukocytosis group (white blood cell count <100,000/µL). We compare these two groups on the response rate after the induction chemotherapy, the median overall survival (mOS), and median disease-free survival (mDFS), then evaluate different treatments and other prognostic factors associated with outcomes. Statistical analyses were carried out using SPSS 24.0. The Kaplan-Meier method and log-rank test were used to assess and compare the survival outcomes. Univariate Cox proportional hazards regression was used to determine associated risk factors for overall survival. A two-tailed P value <0.05 was considered statistically significant. Result: Totally 217 patients were enrolled. To balance the impact factors, 12 patients who received high-dose cytarabine were excluded from the non-hyperleukocytosis group. The cohort ready for analysis had 45 patients in the hyperleukocytosis group and 160 patients in the non-hyperleukocytosis group. Two groups had no significant differences in age; gender, FAB classification; platelet counts and hemoglobin level at initial diagnosis; co-existing intermediate/high-risk mutations according to 2022 ELN risk stratification; treated with high-dose cytarabine, or receiving bone marrow transplantation (all P＞0.05). The median follow-up time was 29.5 months, and 154 patients were still alive at the study endpoint. There were no significant differences in the composite complete remission (CRc) rates (73.3% vs. 79.3%, P= 0.389), mOS (65.0m vs. 56.0m, P= 0.574), and mDFS (54.0m vs. 35.0m, P= 0.855) between two groups. With high-dose cytarabine (2.0-3.0 g/m2 q12h X 3 days for at least three courses) as consolidation chemotherapy, the two groups had no significant difference in mOS (Not reached vs. Not reached, P=0.143) and mDFS (21.0m vs. 35.0, P= 0.352). In order to understand the impact of allo-HSCT on the hyperleukocytosis group, we divided this group into the allo-HSCT subgroup and the non-HSCT subgroup. After balancing on age, gender, presence of high-risk mutations, and MRD negativity after the first remission (all P>0.05), the mOS in the allo-HSCT subgroup (n=16) was significantly longer than the non-HSCT subgroup (n=16) (Not reached vs. 46.0m, P= 0.007). However, the mDFS had no significant difference between the two sub-groups (63.0m vs. 43.0m, P= 0.341). The univariate Cox proportional hazards regression analysis revealed that only age had a significant impact ( P= 0.01), all other factors had no significant effects, including hyperleukocytosis, gender, hemoglobin level, platelet count, intermediate/high-risk mutations, or bone marrow transplantation. Conclusion: In favorable-risk AML, hyperleukocytosis does not lead to an adverse prognosis. Received high-dose cytarabine as a consolidation therapy, favorable-risk AML patients with hyperleukocytosis do not have worse OS or DFS than those without hyperleukocytosis. Allo-HSCT may bring longer OS for hyperleukocytosis patients at favorable risk but may not bring longer DFS. Our results suggest favorable-risk AML patients with hyperleukocytosis can be managed equally as non-hyperleukocytosis patients.

ELN 2022 Favorable Genetic Risk Acute Myeloid Leukemia Treated with Venetoclax Plus Hypomethylating Agent: Predictors of Response and Survival

Background: The 2022 European LeukemiaNet (ELN) genetic-risk stratification for acute myeloid leukemia (AML), assigns favorable prognosis to t(8;21)(q22;q22.1)/ RUNX1:: RUNX1T1, inv(16)(p13.1q22) or t(16;16)(p13.1;q22)/ CBFB:: MYH1, NPM1 mutations without FLT3-ITD or adverse karyotype, and bZIP in-frame CEBPA mutations (Döhner , Blood, 2022 ). This risk stratification was derived from intensively treated patients; accordingly, prognostication in ELN favorable genetic risk AML, following venetoclax and hypomethylating agent (VEN-HMA) therapy, remains unclear and was the subject of the current study. Methods: Under an institutional review board approved minimum risk protocol, the Mayo Clinic database was searched to identify AML patients with favorable genetic risk, who received treatment with VEN-HMA in the frontline setting. All patients received at least one cycle of either azacitidine 75 mg/m 2 days 1-7 or decitabine 20 mg/m 2 days 1-5 with VEN dose adjusted based on azole antifungal prophylaxis. Genetic risk stratification and treatment response were assessed according to the 2022 ELN criteria. Survival was estimated from the time of VEN-HMA treatment start to last follow-up or death. Results: Patient characteristics A total of 46 newly-diagnosed AML patients with ELN 2022 favorable genetic risk [ NPM1 mutation, n=36 (78%), CEPBA bZIP mutation, n=7 (15%) and t(8;21)(q22;q22.1)/ inv(16)(p13.1q22), n=4 (9%)] received a median of 4 cycles (range 1-32) of VEN-HMA. Median age was 71 years, with 63% males, and 87% de novo AML. Additional mutations frequently involved TET2 in 17/43 (40%), DNMT3A in 14/45 (31%), SRSF2 in 10/43 (23%), K/NRAS in 10/45 (22%), IDH1 in 8/46 (17%), FLT3-TKD in 7/46 (15%), ASXL1 in 6/43 (14%) and IDH2 in 6/46 (13%),of informative cases.Myelodysplasia (MDS)-related gene mutations ( ASXL1, RUNX1, BCOR, EZH2, SRSF2, U2AF1, SF3B1, STAG2, and/or ZRSR2) were present in 15 of 40 (38%) of patients (93% males). Predictors of response Of the 39 (85%) patients that achieved complete remission, with (CR) ( n=24; 52%), or without count recovery (CRi) ( n=15; 33%); CR/CRi rates were not significantly higher in patients with NPM1 mutations (89%), t(8;21)(q22;q22.1)/ inv(16)(p13.1q22) (75%), or CEPBA bZIP mutations (67%) ( p=0.37). Among patients achieving CR/CRi, measurable residual disease by multiparametric flow cytometry was negative in 15 of 16 (94%) of evaluable cases after cycles 1 or 2. In addition, NPM1 qPCR was negative in 15 of 24 (63%) informative patients. Median time to response was 1.2 months with median response duration of 9.4 months. CR/CRi rates were significantly higher in females vs males (100% vs 76%, p=0.01), and in the absence vs presence of MDS-related gene mutations (96% vs 60%, p=0.004). Multivariable analysis confirmed superior response in the absence of MDS-related gene mutations ( p=0.04). Predictors of survival At a median follow-up of 10.6 months (range; 1.1-51 months), 21 patients (46%) have died, 9 relapsed (23% of those achieving CR/CRi), and 6 (13%) underwent allogeneic hematopoietic stem cell transplant. Median overall survival was 21 months with 1/2/3-year survival rates of 65%/41%/41% (Figure 1a); median relapse-free survival (RFS) was not reached; 1/2/3-year RFS rates were 81%/66%/57% (Figure 1b). Overall survival was superior in patients achieving CR/CRi (23 months vs 5.6 months; p<0.01), in females vs males (not reached vs 9.7 months; p<0.01), and in the absence of MDS-related gene mutations (not reached vs 5.6 months; p=0.01) (Figure 1c). Subsequent multivariable analysis identified female gender ( p=0.01), and absence of MDS-related mutations ( p=0.17) as independent predictors of superior survival. Similar results were obtained when analysis was restricted to NPM1 mutated patients. Conclusions: In the current retrospective study, VEN-HMA therapy in elderly/unfit AML patients with ELN 2022 favorable genetic risk, resulted in response rates that were comparable to those previously appreciated from published reports of patients receiving intensive induction therapy; however, follow-up in the current study was too short to accurately assess long-term overall and relapse-free survival impact. Our study also highlights the adverse prognosis retained by MDS-related gene mutations.

Disparities in Genetic Profiles, Risk Stratification and Outcomes in Adults with Acute Myeloid Leukemia Comparing Patients of Hispanic and Non-Hispanic Ethnicity in Central California

Acute myeloid Leukemia (AML) is the most common type of acute leukemia in adults. Ethnic disparities due to distinct biology and socioeconomic status have been described in AML. Prior studies indicated Hispanic AML patients had a younger age at presentation, more frequent high-risk mutations, and worse survival compared with non-Hispanics. We conducted a retrospective study to investigate the differences in AML risk stratification, mutational profiles and outcomes between Hispanic and non-Hispanic AML patients treated at Community Medical Centers (CMC) in Central California. Methods: We retrospectively analyzed patients ≥ 18 years diagnosed with AML between January 2016-December 2022 and treated at CMC in Fresno, CA. Patients with Acute promyelocytic leukemia and patients without complete cytogenetic and molecular data were excluded. The clinical data including age, sex, ethnicity, race, zip code, WBC on diagnosis, cytogenetics, molecular data and treatment regimens were reviewed. Molecular profiling was performed by next generation sequencing using established myeloid panels by NeoGenomics (NeoTYPE comprising of 63 genes) or Foundation One Heme laboratory (406 genes). Risk groups were identified based on the European Leukemia Network (ELN) 2022 criteria. RedCap data collection tool was used for data collection. A comparison of patient characteristics and rate of genetic alterations between Hispanic and Non-Hispanic patients was done using the Fisher exact test or Chi-square test. Kaplan-Meier Curve with log-rank test was used for evaluation of overall survival (OS) and progression-free survival (PFS). Results: 201 patients met the study criteria, 30 of them did not receive treatment and were included for their diagnostic data only but excluded from the survival analysis. The mean age at diagnosis was 65.6. 58.5% were males and 30% were Hispanic. Hispanic patients were younger than non-Hispanics (57.6 vs 64.6 years, p=0.01). Hispanic patients were also more likely to live in the relatively low Socioeconomic status (SES) neighborhoods (i.e., living in zip codes with the 1st or 2nd quartile of median income level) p=0. 007. More Hispanic patients needed interpreter P<0.001. However, Hispanics were more likely to experience favorable risk AML (8.4 % vs 0.7%, p=0.012), while non-Hispanics had higher rate of poor risk disease (63.8 Vs 55.9%, p=0.012).). There was no significant difference between Hispanics and non-Hispanics in terms of sex, de novo versus secondary AML, WBC at time of diagnosis, Extramedullary or Central nervous system (CNS) involvement, type of induction regimen or rate of consolidative or subsequent allogeneic stem cell transplant. Median OS in Hispanics was 17.3 months compared to 10.28 months for non-Hispanics, p=0.117.and median PFS for Hispanics was 9.17months compared to non-Hispanics at 6.04 months P=0.034 (Figure 1). In univariate analysis PFS and OS were better in patients with normal cytogenetics compared to those with abnormal cytogenetics (15.3 vs 3.52 months and 20.4 vs 7.69 months respectively, p < 0.001) and in patients with favorable compared to intermediate risk and poor risk groups (84.5 vs 11.4 vs 4.1 months for PFS and Non reached vs 18.1 vs 7.8 months for OS, p< 0.001). There was no significant effect of income level in terms of OS or PFS. The most common genetic mutations in our patients were NPM1, FLT3-ITD, DNMT3A, TET2 and TP53. However, there were differences in the rates between Hispanics and non-Hispanics. 5q deletion and STAG2 were more common in non-Hispanics while KMT2C was detected more in Hispanics (table 1). Conclusion: Our study identified biologic differences between Hispanic and non-Hispanic AML patients with heterogeneity in genetic mutations. While Hispanic patients had lower income, they were younger at diagnosis and more likely to have favorable risk AML. Hispanic patients had better PFS and a trend towards improvement in OS. Further studies on larger patient population are warranted to evaluate the effect of ethnicity and SES on outcomes of AML patients.

A Comparison of Somatic Mutations and ELN Classification in De Novo Acute Myeloid Leukemia between Appalachian and Non-Appalachian Kentucky

Introduction The Appalachian region's cancer mortality rate is 10% higher than the national rate. Central Appalachia, which is predominantly in Kentucky, exceeds the national average by 35%. Appalachian Kentucky has higher mortality rates for prostate, lung, cervical, and head and neck cancers compared to non-Appalachian Kentucky. This can be attributed to health care disparities, environmental factors, and unique genomic characteristics of the tumors seen in the Appalachian population. Based on this, we hypothesized that patients with acute myeloid leukemia (AML) in Appalachian Kentucky would have worse outcomes and higher mutational burden compared to patients in non-Appalachian Kentucky. To test this hypothesis, we compared overall survival (OS) and frequency of molecular mutations between patients from Appalachian (ApK) and Non-Appalachian Kentucky (Non-ApK). Methods A single-center retrospective analysis was done utilizing the Kentucky Cancer Registry (KCR) to identify patients with De Novo AML from January 2015 to January 2021. Patients with available cytogenetic and somatic mutations profile from next-generation sequencing (NGS) were included. Demographic, clinical, laboratory, and pathologic data were obtained from clinical records. Statistical analysis was done using the Mann-Whitney U test for continuous variables and proportions were compared using Chi-square test. The Kaplan-Meier curves were used for overall survival. Results A total of 225 patients with de novo AML were identified. The median age at diagnosis was 61 (range, 21-86). The population was fairly distributed among males (52%) and females (48%). Approximately 56% (n=127) of patients were from ApK and 46% (n=98) were from non-ApK. Of the patients from ApK, approximately 22% (n=29) had favorable risk AML per the ELN 2022 classification, while 24% (n=30) had intermediate and 54% (n=68) had poor risk AML. This was not statistically different from the Non-ApK patients where 22% (n=22) had favorable, 21% (n=21) had intermediate, and 56% (n=55) of patients had poor risk AML (Table 1). The median number of clinically significant mutations were also similar between the two groups (p value = 0.47). The most commonly occurring somatic mutations were NPM1, DNMT3A and FLT3-ITD, which occurred at similar frequencies between the ApK and non-ApK cohorts. There was no difference in the median overall survival between the two cohorts (17 versus 22 months, p =0.47; 90% CI). Median OS and 1-year OS for the entire cohort were 21 months and 47.1%, respectively. Conclusions This study demonstrated that the outcomes of de novo AML is similar for patients from Appalachian versus Non-Appalachian Kentucky when treated at an Academic Medical Center. There were no statistically significant differences between ELN 2022 risk classification and mutational abnormalities tested between these two groups. This suggests that the biology in de novo AML is similar in both ApK and non-ApK patients.

Azacitidine, Venetoclax and Allogeneic NK Cells in Newly Diagnosed Acute Myeloid Leukemia (ADVENT-AML): An Investigator-Initiated Multicenter Phase Ib Trial

BACKGROUND AND SIGNIFICANCE : Older/unfit patients with acute myeloid leukemia (AML) have limited treatment options. Outcomes in adverse-risk subgroups of AML are modest with CR/CRi rates of 45% to 60% and median overall survival (OS) of 5 to 12 months with current standard frontline therapy of hypomethylating agent with venetoclax (HMA-VEN).While allogeneic stem cell transplantation (allo-SCT) can significantly improve OS in AML, only 10 to 20% of older pts are able to undergo allo-SCT (Pratz et al. Blood 2019, Maiti et al. Blood 2022) Natural killer (NK) cells bridge the innate and adaptive immune system and play a major role in graft-vs-leukemia (GVL) effect responsible for the clinical benefit noted with allo-SCT. NK cell-based adoptive cellular therapies have shown good safety profiles and promising activity in AML with responses noted in 25% to 88% of patients. Furthermore, NK cells are less likely to induce graft-versus-host disease (GVHD), severe cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome (ICANS). We hypothesize that the combination of azacitidine, venetoclax and allogeneic NK cells will be safe and improve cure rates in AML compared to either Aza/Ven or NK cells alone. Improved clinical activity may be mediated through multiple synergistic mechanisms including reduction of disease burden by Aza/Ven, upregulation of epigenetically silenced NKG2D ligands, dual activation of extrinsic and intrinsic apoptotic cascades, mitochondrial priming of leukemia cells by venetoclax, and bypassing significant morbidity and mortality associated allo-SCT. Significance: This will be the first trial to evaluate 1) cellular therapy in the frontline setting in AML; 2) the synergy of venetoclax with adoptive NK cell therapy; and 3) Aza/Ven as a lymphodepletion strategy. The results will have significant impact on the development of cellular therapies for hematological and solid tumors. STUDY DESIGN AND METHODS: This investigator-initiated, multicenter, open-label, phase Ib study will evaluate the combination of azacitidine, venetoclax and ex vivo-expanded, off-the-shelf cryopreserved allogeneic NK cells in patients with AML (NCT05834244). Eligibility criteria: The dose escalation phase will enroll adults with relapsed or refractory AML or MDS/AML, and the dose expansion phase will enroll older/unfit pts with newly diagnosed adverse-risk AML. Eligible Pts will be ≥ 75 years, or ≥ 18 years with at least one protocol-defined comorbidity. Patients with favorable risk AML, poor end-organ function, needing immunosuppression, uncontrolled infection or CNS leukemia will be excluded. Trial design: The dose escalation phase will enroll a maximum of 12 patients at 2 dose levels to establish a recommended phase 2 dose (RP2D) using a BOIN design. The dose expansion will enroll up to 20 patients at the RP2D ( Fig. 1). Study treatment: Patients will receive Aza/Ven as standard. Two dose levels of NK cells including 0.5 x10 9 and 1 x10 9 flat dose on day 8 and 15 of the first 4 cycles will be evaluated. Subsequently, pts will continue Aza/Ven indefinitely. Objectives: The primary objective is to determine the safety of this novel triplet combination in terms of dose-limiting toxicities including acute GVHD, CRS or ICANS. Secondary objectives include overall response rate, CR/CRi by 4 cycles, rate of negative measurable residual disease, OS and relapse-free survival. Exploratory objectives include additional response and survival endpoints, the persistence of NK cells using SNP-NGS chimerism, kinetics of allorejection, remodeling of host immune microenvironment and impact on AML stem/progenitor cell hierarchies using single cell CyTOF to understand response/resistance mechanisms. Status: Trial approved by the FDA and institutional IRB. Activation planned for 2H 2023. Funding: Gateway for Cancer Research, MDACC PRIME Award, Chimeric Therapeutics, NCI Cancer Center Support Grant.

Venetoclax in Combination with Intermediate Doses of Cytarabine in Consolidation Phase for Acute Myeloid Leukemia Patients in First Complete Remission; Results of the Part 1 of the Phase 1/2 Multicentric Covenidac Study

For authors: Please: L Gastaud and P Peterlin: co-primary, H dombret et C Recher: co-last Background: The French ALFA-FILO AML intergroup launched the BIG-1 trial (EudraCT No.: 2014-000699-24) in 2015 to evaluate different intensive chemotherapy (ICT) strategies aiming at improving the survival of younger adults with acute myeloid leukemia (AML). All patients (pts) with previously untreated non-APL and non-CBF AML aged 18-60 years were eligible for this trial. The trial design included several randomization types. Results of the R1 and R2 randomizations, namely idarubicin vs daunorubicin for induction and IDAC vs HDAC for consolidation, will be reported at this meeting. In patients who achieved first complete remission (CR), randomizations R4 consisted of nested randomized Phase 2 or 1/2 studies evaluating the addition of new drugs to the IDAC/HDAC consolidation cycles. The protocol was designed to allow several sequential multicenter R4 evaluations of various new agents over the trial period. Venetoclax (VEN) has proved its efficacy when combined to azacitidine or low dose cytarabine in unfit AML pts (DiNardo et al. 2020; Wei et al. Blood 2020). Its role in fit patients treated with ICT is still under investigation. The COVENIDAC Phase 1/2 R4 sub-study is evaluating the safety and efficacy of VEN added to IDAC during the consolidation cycles of CR pts. We report herein the result of the Phase 1 part. Methods: The primary objective of this Phase 1 study was to determine the maximum tolerated dose (MTD) of VEN in combination with IDAC during the consolidation cycles, which will be the recommended dose for the Phase 2 (RP2D). Dose limiting toxicities (DLTs) were assessed during the first cycle of consolidation (C1) according to a 3+3 design. A maximum of 3 consolidation cycles was planned depending on the AML risk group. Hematological DLT was defined as no peripheral blood count recovery within 56 days from day 1 of the cycle. Non-hematological DLTs were defined as Grade ≥4 toxicities or Grade ≤3 toxicities which have not recovery by day 56 and deemed related to VEN per investigator opinion. VEN was started at dose level (DL) 1: 100 mg/d from day 1 to 8. In the absence of DLTs at DL1, 3 others DL were planned: 200 mg/d from day 1 to 8 (DL2); 400 mg/d from day 1 to 8 (DL3), and 400 mg/d from day 1 to 14 (DL4). IDAC was administrated at 1.5 gr/m² twice daily on day 1/3/5 for DL1, DL2 and DL3 pts, then on day 1/2/3 for DL4 pts after a protocol amendment. Main inclusion criteria were: pts in first CR following 1 or 2 courses of induction chemotherapy fit for further ICT; favorable and intermediate risk AML as defined by the protocol; ECOG PS ≤2; written informed consent. Measurable residual disease (MRD) was assessed by multiparametric flow cytometry (MFC) in all pts as well as NPM1-qPCR in NPM1-mutated pts. Results: Between 06/2021 and 04/2022, 15 pts from 9 centers were screened and enrolled. Pt characteristics were as follows: median age, 42 years (IQR, 30-49); 2 males/7 females; ECOG-PS, 0 in 10 pts and 1 in 5 pts; favorable/intermediate/adverse ELN-2017 risk, 9/2/4. Neutropenia and thrombocytopenia durations are shown in Table 1. Only 1 hematological DLT was observed at DL3 (platelet count of 96 giga/L at day 56 in a patient who was infected by Covid-19). Overall, there were very few non hematological AEs ( Table 2, no grade 4) and only 4 SAEs (1 related to IDAC/VEN during C1, 3 non-related). No non-hematological DLT was observed. No patient died during the DLT observation period, 1 experienced a septic shock (C2, DL2). One pt received only C1 (due to DLT), 7 received 2 cycles, and 7 received 3 cycles. Median time between initiation of subsequent consolidation cycles was 37.5 days (IQR, 35-41) for C1/C2 and 40 days (IQR, 35-43) for C2/C3. One pt had to stop VEN during C3. Six pts received an allogeneic HSCT (5 in CR1, 1 after salvage). With a median follow-up of 13.5 months, 3 pts relapsed and 2 died. MRD results will be presented. Conclusion: VEN/IDAC combination appears to be feasible and safe as consolidation therapy, with expected thrombocytopenia and neutropenia durations. These durations appeared even shorter at DL4, when IDAC was given on 3 consecutive days. VEN at 400 mg/d from day 1 to 14 combined with IDAC on day 1/2/3 was thus retained as RP2D for the randomized Phase 2 with RFS as primary endpoint. This phase 2 has already recruited 29 of the 200 pts planned.

ELN Risk Stratification Is Not Predictive of Outcomes for Treatment-Naïve Patients with Acute Myeloid Leukemia Treated with Venetoclax and Azacitidine

Background: Venetoclax (Ven), a highly selective oral BCL-2 inhibitor, in combination with hypomethylating agents (HMAs) such as azacitidine (Aza), is approved for the treatment of patients (pts) with newly diagnosed acute myeloid leukemia (AML) who are ineligible for intensive chemotherapy (IC). An open-label, non-randomized phase 1b trial (NCT02203773) and the confirmatory VIALE-A phase 3 randomized trial (NCT02993523), both enrolling pts with intermediate and poor risk cytogenetics per NCCN Guidelines, demonstrated that the combination of Ven+Aza led to high rates of complete remission and longer overall survival (OS) than Aza alone (median OS of 14.7 months [mo] vs 9.6 mo), with similar safety profiles. In this exploratory post hoc analysis of the pooled treatment-naïve, IC ineligible pts treated with Ven+Aza in the phase 1b and phase 3 trials, patients were stratified according to the 2017 ELN risk classification system (which is based on data from patients receiving IC and utilizes cytogenetic and molecular determinants commonly associated with AML). We report clinical outcomes for these patients per ELN 2017 risk group, which will also be updated using the newly published ELN 2022 criteria. Methods: For the phase 1b trial, our analysis includes pts who were enrolled to evaluate safety and efficacy of Ven+Aza at a daily dose of 400 mg for VEN. For the phase 3 trial, pts were randomly assigned in a 2:1 ratio to the Ven+Aza group or placebo (Pbo)+Aza group. All pts received a standard dose of Aza (75 mg/m2 SC or IV on days 1-7 every 28-day cycle). Ven (400 mg) or Pbo was administered orally, once daily, in 28-day cycles. Pts with favorable risk cytogenetics such as t(8;21), inv(16), t(16;16) or t(15;17) as per the NCCN Guidelines Version 2 were excluded from the study. The pooled group of pts from the two trials having both site-reported cytogenetic data and bone marrow aspirate with centrally determined molecular data allowing for ELN genetic risk classification were included in this analysis. Pts were retrospectively classified per the ELN 2017 criteria as favorable-, intermediate-, or adverse-risk AML. Results: Inclusion of central molecular data allowed the reclassification of patients according to ELN 2017 recommendations (Figure 1). 63 of the 67 Ven 400mg + Aza pts enrolled in the phase 1b trial, and 329 of the 431 total pts enrolled in the VIALE-A trial were evaluable for inclusion in this analysis (279/353 in the pooled Ven+Aza group and 113/145 in the Pbo+Aza control group from the phase 3 study). In the Ven+Aza and Pbo+Aza groups, 46 (16.5%) and 20 (17.7%) pts had favorable-risk AML, 65 (23.3%) and 19 (16.8%) had intermediate-risk AML, and 168 (60.2%) and 74 (65.5%) had adverse-risk AML, respectively, by ELN. In favorable-risk AML pts, CR+CRi was achieved in 69.6% with VEN+AZA vs in 20% with Pbo+Aza; for intermediate-risk AML, CR+CRi was achieved in 75.4% vs 42.1%; for adverse-risk AML, CR+CRi was achieved in 61.3% vs 25.7%. Median OS was longer with Ven+Aza in all three risk categories when compared to Pbo+Aza: 21.09 vs. 12.96 mo, HR = 0.45 [95% CI: 0.24, 0.83] in the favorable-risk group; 23.26 vs. 13.14 mo, HR = 0.62 [95% CI: 0.35, 1.08] in the intermediate-risk group; 11.53 vs. 7.43 mo, HR = 0.59 [95% CI: 0.43, 0.82] in the adverse-risk group. The median OS was similar for favorable and intermediate risk groups who received Ven+Aza (21.09 mo and 23.26 mo, respectively; Figure 2). While the median OS of the Ven+Aza adverse risk group was lower (11.53 mo), two subgroups with distinct outcomes are apparent: adverse risk pts with a TP53 mutation (36.3% [61/168]) and adverse risk pts with a RUNX1 mutation (40.5% [68/168]) (one pt had both TP53 and RUNX1). The median OS for adverse risk pts with a RUNX1 mutation and TP53 WT was 22.9 mo while the median OS for adverse risk pts with a TP53 mutation and RUNX1 WT was 5.42 mo. Conclusions: ELN 2017 risk groups, based on younger patients who received IC regimens, are not prognostic in patients receiving Ven+Aza. This exploratory analysis suggests little OS distinction between favorable and intermediate risk groups. Furthermore, adverse risk ELN groups can be further refined to determine mutationally-defined cohorts with more favorable outcomes. A modified risk stratification system is needed for pts receiving newer therapies, such as Ven+Aza, that uses determinants that are prognostic for pts treated in the context of these regimens with distinct mechanisms of actions from IC. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Interferon-α-2b As a Maintenance Therapy Gain a High Rate of MRD Negative Conversion and Improve RFS in Patients with Favorable-Risk Acute Myeloid Leukemia----a Prospective, Single-Arm Study

Background: Maintenance therapy in favorable-risk is still controversial, so the maintenance therapy of AML is of great concern. Interferon-α (IFN-α), a type Ⅰ IFN, is a well-known antitumor agent, which has an immunoregulatory function. Several studies have shown that IFN has a definite therapeutic effect on AML. Indeed, studies have reported that IFN-α as maintenance therapy in patients with AML can prevent leukemic relapse. However, the only randomized controlled trial (RCT) that explored the role of IFN-α as maintenance therapy in AML found no difference between the comparison groups in remission duration, overall survival (OS), disease-free survival (DFS) or relapse-free survival (RFS). In our previous respective studies, IFN-α-2b as a maintenance therapy may reduce the relapse rate in patients with favorable-risk AML after consolidation chemotherapy. Moreover, IFN-α-2b could effectively control minimal residual disease (MRD) in acute leukemia/myelodysplastic syndrome after allogeneic hematopoietic stem cell transplantation (HSCT). The aim of this study was to evaluate the efficacy and safety of IFN-α-2b in the maintenance of favorable-risk AML. Method: This is an interim analysis of an ongoing clinical prospective study (trial registration number: ChiCTR2000035310) of a planned 31 favorable-risk (NCCN Guideline) AML patients with MRD positive who underwent 1-2 therapeutic induction chemotherapy for complete hematologic remission (CR) and completed 4-6 courses of consolidation chemotherapy. MRD positive was defined as detectable MFC-MRD >0.1% or fusion genes level decreased by >3 log. 22 patients were recruited in our study to date. Patients were administered with 3 million U of IFN-α-2b three times a week for 18 months. Bone marrow assessments were performed on the 2nd, 5th, 8th, 11st, 14th, 18th month since IFN-α-2b therapy. The primary objective is to determine the cumulative rates of MRD negative conversion, 3-year RFS and adverse reactions. Results: Patients were classified as favorable-risk category according to cytogenetics and molecular biology. 22 participants with favorable-risk AML were enrolled in this study, and 2 of them received IFN-α-2b less than 3 months, who were not evaluated in this report. The molecular biological characteristics of this study were AML-ETO+/c-KIT- 11 cases; AML-ETO+/c-KIT+ 2 cases (T417_D419delinsIP); CBFβ-MYH11+/C-KIT- 5 cases; CBFβ-MYH11+/C-KIT+ 2 cases (Y418_D419insFF, D816Y); NPM1+/FLT3-ITD- 3 cases; and CEBPA double mutation 1 case. The median age of the 22 participants was 47.5 (18.0-66.0) years old. Outcome data were updated as of July 2022, for a median follow-up 13.5 (6.6-24.0) months of the 20 patients received IFN-α-2b more than 3 months, and the median duration of treatment was 13.5 (5.2-18.0) months. Among 20 evaluated patients, the cumulative rates of MRD negative conversion is 66.7±11.0% after the median time of 4.4 (1.1-8.1) months IFN-α-2b treatment (Figure 1). As for recurrence, 2 patients had hematologic recurrence, with the estimated rate of 2-year RFS was 86.1±9.4% (Figure 2). Meanwhile, there are 5 persistent MRD positive participants, 3 of them got decreased MRD level for 1 log-fold, 1 case got increased MRD level for 2 log-fold, and MRD level did not decline in 1 case. The regimen was well tolerated. In terms of safety, the most frequent nonhematologic adverse events were fever (11/20, 55.0%) after IFN-α-2b therapy. 4/20 (20.0%) developed hematologic toxicity which were thrombocytopenia, 1/20 (5.0%) had muscle pain, 1/20 (5.0%) elevated hepatic transaminases, 1/20 (5.0%) developed rash. Conclusion: IFN-α-2b as maintenance therapy for CR1 patients with favorable-risk AML gain a high rate of MRD negative conversion and high rate of 2-year RFS Interferon therapy is safe and well-tolerated. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Updated Results of CPX-351 in Combination with Gemtuzumab Ozogamicin (GO) in Relapsed Refractory (R/R) Acute Myeloid Leukemia (AML) and Post-Hypomethylating Agent (Post-HMA) Failure High-Risk Myelodysplastic Syndrome (HR-MDS)

Background: Treatment outcomes in patients (pts) with AML and HR-MDS who progress after HMA +/- venetoclax (VEN) based regimen remains poor and warrants new therapeutic strategies. CPX-351 (Vyxeos™) is a dual liposomal formulation of cytarabine and daunorubicin, at a fixed synergistic 5:1 molar ratio, approved by US Food and Drug Administration (FDA) for the treatment of newly diagnosed therapy-related AML or AML with myelodysplastic related changes (AML MRC). GO (Mylotarg™) is a humanized IgG4 antibody directed against CD33 and conjugated to the DNA toxin calicheamicin and approved by the FDA for the treatment of newly diagnosed or R/R CD33-expressing AML. We hypothesized that the combination of CPX-351 and GO could be synergistic in this high risk pt population and have potent anti-leukemic activity. Aim: To determine the safety and efficacy of CPX-351 in combination with GO in patients with R/R AML or post-HMA failure HR-MDS. Methods: We present here the updated results of the Phase 2 single-arm pilot study (NCT03672539) of CPX-351 and GO (CPX-GO) combination therapy in pts with CD33 positive R/R AML or post-HMA failure HR-MDS. Pts received induction cycle (C) CPX-351 (daunorubicin 44 mg/m2 and cytarabine 100 mg/m2) administered via intravenous (IV) infusion on days (D) 1, 3, and 5. GO was administered at a dose of 3 mg/m2 (capped at 4.5 mg) IV on D1. Pts not attaining complete remission (CR) or CR with incomplete count recovery (CRi) after C1, could receive a 2nd induction cycle of CPX at the same dose, but only on D1 and D3 with GO 3 mg/m2 on D1. Pts attaining CR/CRi could receive up to 2 consolidation cycles, after a minimum of 4 weeks from the start of the previous cycle with CPX (daunorubicin 29 mg/m2 and cytarabine 65 mg/m2) IV on D1 and D3 and GO at 3 mg/m2 on D1. GO was only administered during the second consolidation cycle if there was evidence of measurable residual disease (MRD+) as measured by flow cytometry. GO could also be administered as a single agent for maintenance treatment on D1 every 6 weeks, in case of persistent detection of MRD. CD33 genotyping to assess for GO sensitivity was available for a subset of pts. Response was denoted as per the ELN 2017 criteria for AML and IWG 2018 criteria for MDS. Results: From Nov 2018- Apr 2022, 31 pts were treated on the trial, 29 (93%) pts with AML and 2 pts (7%) with HR-MDS. Baseline disease, treatment and response characteristics are mentioned in Table 1. The median lines of prior AML therapy were 2 (range, 1-6). Eleven pts (38%) had baseline de novo AML, while 15 (52%) and 3 (10%) pts had secondary (s-AML) and therapy-related (t-AML) AML respectively. Twenty-three AML pts (79%) had prior VEN exposure. Both the prior HR-MDS patients had bone marrow (BM) blasts >15% and one pt had prior VEN exposure. Overall, 21 pts with AML (72%) were adverse risk and only 1 pt (3%) had favorable risk AML (diploid karyotype with NPM1 mutation). Four pts (all AML; 13%) had undergone a prior stem cell transplantation (SCT). The median number of cycles on trial were 1 (range, 1-6). At the time of data cutoff, none of the pts were on active study therapy and the median follow up was not reached. Sixteen pts (52%) had an overall response; 9 pts had CR/CRh/MLFS (8 AML and 1 MDS= responders), after a median of 1 cycle of therapy, and 7 pts had a partial response (all AML). CD33 genotype did not affect response rates (no response in 5 pts with C/C vs 2/6 responders in C/T genotype, p=0.45). Amongst prior VEN exposed pts, 5/24 (21%) responded versus 3/7 (43%) non VEN exposed pts (p=0.15) One pt could directly proceed to a SCT in CR after the trial therapy. For relapse free survival (RFS) analysis partial responders were grouped under non-responders. The median RFS and overall survival (OS) for the whole cohort was 6.3 and 6.8 months (mos) respectively, and median OS was 12.9 mos for responders(Fig. 1). One pt had a grade 2 infusion reaction to GO. Overall, adverse events at least possibly attributed to the trial medications were seen in 5 pts, of which 2 events were ≥ grade 3 (mucositis and seizures). No pt had hepatic veno-occlusive. Eight pts (all non-responders) (26%) died on the trial from infections/leukemia progression and there were no deaths in remission. Conclusion: In a cohort composed predominantly of heavily pre-treated and VEN exposed adverse risk AML and HR-MDS pts, CPX-GO led to overall response (CR/CRh/MLFS/PR) rates of 52% and year-long median survival in responders (CR/CRh/MLFS) with no major non-hematological adverse event. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

The Adverse Effect of Myelodysplasia-Related Mutations in De Novo Acute Myeloid Leukemia Is Associated with Higher Variant Allelic Frequency (VAF): A Proposal for a Numeric Cutoff for Variant Allelic Frequency

Mutations in myelodysplasia-related genes ASXL1, BCOR, EHZH2, RUNX1, SF3B1, SRSF2, STAG2, U2AF1 and ZRSR2 (MRmut) are class-defining alterations in acute myeloid leukemia (AML) in the latest World Health Organization (WHO, with the exception of RUNX1) and International Consensus Classification (ICC) schemes and indicate adverse-risk per European Leukemia Net (ELN) 2022 guidelines, unless occurring in favorable-risk AML. The lower limit of detection (LOD) for most clinical-grade next generation sequencing (NGS) is ~1-2% variant allelic frequency (VAF); however, data on the prognostic significance of MRmut relative to VAF is lacking. No guidelines that provide a numeric cutoff for VAF are available for utilizing these mutations to classify AML. Our aim was to define a clinically meaningful VAF cutoff for MR mutations in de novo AML. We included patients (pts) with de novo, untreated AML with MRmut treated at our institution between 2017 to 2022. We excluded pts with acute promyelocytic leukemia, core binding factor AML, and other ELN adverse-risk categories (adverse karyotype and/or TP53 mutation). NGS at baseline was performed using a panel of 81 genes recurrently mutated in myeloid neoplasms (LOD ~1-2%). We performed a best fit classifier on individual MRmut to determine optimal VAF cutoffs using event-free survival (EFS) and overall survival (OS) as endpoints. VAF for MRmut involving X-linked genes was adjusted for men. Pts (n=145) included 92 (63%) men and 53 (37%) women with a median age of 68 years (range, 58-75). 85 (59%) pts had diploid karyotype AML, 51 (35%) had other intermediate-risk non-diploid karyotype AML, and 9(6%) had insufficient metaphases for analysis. 34 (23%) pts had ELN favorable-risk and 111(77%) had ENL adverse-risk AML. Pts were treated with low-intensity+venetoclax (VEN) (72/50%), low-intensity (26/18%), high-intensity (22/15%), and high-intensity+VEN (12/17%) regimens. Median follow-up was 26.9 months (range, 13.9 - 40.8). 72 (49%) pts had 1 MRmut; the remaining had 2-4 concurrent MRmut. MRmut had the following frequencies and VAFs: ASXL1 (28%; median VAF: 26%, [range 2-48%]); BCOR (18%; median VAF 37% [3-100%]); EHZH2 (9%; median VAF 7% [1-55%]), RUNX1 (32%; median VAF 47% [1-96%]), SF3B1 (9%; median VAF: 38% [1-55%]), SRSF2 (46%; median VAF: 37% [1-76%]), STAG2 (20%; median VAF: 44% [15-98%]), U2AF1 (12%; median VAF: 33% [2-43%]) and ZRSR2 (2%; median VAF: 94% [93-95%]). 34 (23%) pts had ELN favorable-risk AML including 28 (23%) with mutated NPM1 without FLT3-ITD and 6 (4%) with CEBPA bZIP mutations, respectively; in 12/34 pts NPM1 or CEBPA bZIP mutations were subclonal compared with clonal MR mutation(s). A summary of baseline genetic and treatment data is provided in Fig 1A. The overall composite remission rate (CR+CRi) was 88% (64% and 24%, respectively) Median OS was 30.3 months and estimated 12/24 month OS were 77%/60%. The median EFS was 24.6 months and estimated 12/24 month EFS were 65%/51%. Pts with ELN favorable-risk AML with MRmut had longer OS and EFS compared with the adverse-risk group (median OS 34.9 vs 27.5 months, median EFS 34.9 vs 22.9 months) but the difference was not significant (p=0.60 and 0.30, respectively). The VAF cutoff for MRmut associated with EFS and OS, respectively, was: ASXL1: 21%/21%, BCOR 25%/25% , EHZH2 15%/15%, RUNX1 25%/27%, SF3B1 31%/31%, SRSF2 32%/35%, STAG2 40%/21%, U2AF1 44%/44% and ZRSR2 47/47%.There was no significant difference in OS or EFS between pts with 1 MRmut vs those involving ≥2 MR genes. Pts treated with high-intensity, high intensity+ VEN and low intensity+VEN regimens had longer OS (Fig 1B) and EFS compared with pts treated with low intensity regimens without VEN (OS: not reached, 31.7 months, 31.4 months vs 8.9 months, respectively, p<0.001; EFS: not reached, 31.7 months, 29.6 months vs 3.7 months, respectively, p<0.001). Our data suggest that the poor prognostic effect of MRmut in de novo AML is associated with higher VAF and not a binary presence or absence of MRmut. The minimum VAFs associated with worse outcome for each MRmut ranged from 15-47%. Additional analysis to create predictive models is in progress to determine the optimal VAF cutoff when using MRmut to assign AML to the WHO/ICC MR categories and to ELN adverse-risk group. Importantly, our results suggest that pts with MRmut and non-adverse karyotype have significantly better outcomes when treated with high-intensity and/or venetoclax-based treatment regimens. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

A Chemo-Free Bridge-to-Transplant Strategy with Venetoclax and Azacitidine for NPM1-Mutated Acute Myeloid Leukemia in Molecular Failure

Background: In patients (pts) with NPM1-mutated acute myeloid leukemia (AML) fit for intensive chemotherapy, the persistence, reoccurrence, or progression of NPM1mut transcript identifies poor chemotherapy responders that require allocation to allogeneic stem cell transplantation (alloSCT). Currently, there is no standard of care for pts in molecular failure and the proper bridging strategy to alloSCT still needs to be defined. The combination of Venetoclax (VEN) and Azacitidine (AZA) offers an alternative chemo-free strategy with favorable toxicity profile in NPM1mut AML, a molecular subset exquisitely sensitive to VEN. Aims: To characterize a series of NPM1mut AML pts in molecular failure who received VEN-AZA as bridge-to-transplant treatment strategy. Methods: We explored the off-label combination of Venetoclax (VEN) and Azacitidine (AZA) in 9 NPM1mut fit AML pts in molecular failure after intensive chemotherapy eligible for alloSCT, treated at 4 Italian Hematology Institutions. Disease was monitored on bone marrow (BM) with NPM1mut-specific qRT-PCR assay. The quantitative detection limit of the assays was 0.01%. Complete response with minimal residual disease negativity (CR-MRDneg) was defined as ratio NPM1mut/ABL x 100 transcript < 0.01 copies Results: Of the 9 pts analyzed 4 (44%) were female, median age at diagnosis was 56 years (range 41-66) and 58 years (range 43-68) at VEN-AZA therapy. Eight of the 9 pts had ELN2017 favorable-risk AML (2 pts with concomitant FLT3-ITDlow and 1 FLT3-TKD) and 1 pt had intermediate-risk AML (FLT3-ITDhigh). Pts received in median 4 (range 2-5) cycles of front line chemotherapy. Seven pts were treated for molecular relapse and 2 for molecular persistence/progression. All pts received full VEN dosage (400 mg/die or 100 mg/die if concomitant strong CYP3A4 inhibitor) and AZA 75 mg/m2/die s.c. in 5- or 7-day schedule. All pts but 1 performed VEN ramp-up. Pts received a median of 3 cycles (range 1-4). No AZA dose reduction occurred. Median VEN duration during cycle (C)1 was 25 days (range 14-28), 21 days (range 7-28) in C2, 24.5 days (range 7-28) in C3 and 25.5 days (range 19-28) in C4. VEN dosage reductions were due to hematological toxicity ≥ G3 in 60% of cases and in 40% for logistic reasons. The observed ≥ G3 toxicities were neutropenia in 4/9 (44%) pts, 1 thrombocytopenia and 1 febrile neutropenia, managed out-patient. No tumor lysis syndrome was observed. Best response to VEN-AZA was CR MRDneg (NPM1mut undetectable) in 7/9 (78%) pts, reached after a median of 2 cycles (range 1-4). Importantly, no pts relapsed ongoing therapy; 1 pt, notably the FLT3-ITDhigh pt, in CR MRDpos presented molecular progression after C3. Median time from VEN-AZA start to alloSCT was 4.3 months (range 1.7-8.1). At pre-transplant evaluation 6/9 (67%) pts were in CR MRDneg. Eight of 9 pts received myeloablative conditioning and 1 pt received reduced-intensity conditioning. With a median follow-up from alloSCT of 9.3 months (range 2.4-24.0) all patients are alive and 8/9 (89%) in CR MRDneg. Four pts presented NPM1mut reoccurrence after alloSCT: in 2 pts CsA tapering achieved molecular negativity, 1 pt underwent prophylactic therapy with sorafenib and 1pt is currently in CR MRDpos. In no pts FLT3 mutations were detected and, most importantly, no patients experienced morphological relapse. Conclusions: VEN-AZA demonstrated to be a safe and effective bridging regimen for NPM1mut AML pts in molecular failure, allowing to achieve deep responses in the majority of pts at the expense of low toxicity. These preliminary encouraging results will be explored in the GIMEMA AML2521 trial in the same patient subset (clinicaltrials.gov NCT04867928).

Outcome Prediction By the New 2022 European Leukemia Net (ELN) Genetic-Risk Classification for Adult Patients (Pts) with Acute Myeloid Leukemia (AML): An Alliance Study

Background: Since their 1st edition, published in 2010, the ELN recommendations for diagnosis and management of AML include genetic-risk classifications that have become an integral part of clinical practice guiding assessment of the likelihood of AML pts to respond to therapy and achieve long survival. The updated 2022 ELN include a revised genetic-risk classification that incorporated recent advances in molecular genetics of AML. Major changes from 2017 ELN include 1) addition of 7 myelodysplasia(MDS)-related mutations (mut) to adverse (adv) group; 2) placing NPM1-mutated pts with adv cytogenetic abnormalities in the adv group; 3) consideration of only FLT3-ITD, not allelic ratio; 4) replacing biallelic CEBPA mut with bZIP in-frame CEBPA mut as favorable (fav) markers. Additionally, t(3;v)(q26.2;v)/MECOM and t(8;16)(p11;p13) were added to the adv group and karyotypes with ≥3 trisomies excluded from adv group. The goals of our study were to test how well the 2022 ELN genetic-risk groups associate with treatment response and overall survival (OS), compare performance of the 2022 and 2017 ELN classifications in all pts with AML and in cohorts separated by pt age, and assess the validity of newly introduced features. Methods: We analyzed outcomes of 1,098 adult pts with AML similarly treated with cytarabine/anthracycline induction on frontline Cancer and Leukemia Group B/Alliance for Clinical Trials in Oncology protocols between 1986 and 2016 who were categorized according to the 2022 and 2017 ELN genetic-risk classifications. Centrally reviewed cytogenetic and molecular data required by ELN were available for all pts. Results: According to the 2022 ELN classification, 38% of pts were assigned to fav, 26% to intermediate (int) and 36% to adv groups. This represents a decrease in the size of fav and increase in the size of adv groups compared with 2017 ELN classification (fav: 43%, int: 25%, adv: 32%). CR rates reflected well the risk-group assignments, with 90% for fav, 74% for int and 52% for adv groups (P<.001), as did OS (5y rates: fav, 51%, int, 27%, adv, 13%, P<.001). However, there was no difference in outcome prediction when we compared the 2022 ELN and 2017 ELN classifications for all pts (ROC for CR, 2022 ELN: 0.72, 2017 ELN: 0.74; ROC for OS, 2022 ELN: 0.70, 2017 ELN: 0.69, Fig. A). This was also true for pts age <60y and those ≥60y. A major change in the 2022 ELN was 1) the addition of MDS-related gene mut as a criterion for adv group assignment, unless they co-exist with "favorable-risk AML subtypes". Indeed, pts with MDS-related mut and no fav features had poor outcome similar to the outcome of pts with other adv markers (CR, 49 vs 56%, P=.22; OS, 5y rates: 12 vs 16%, P=.33). The outcome of pts with MDS-related mut without fav features was worse than outcome of pts with MDS-related mut co-occurring with fav markers (CR, 49 vs 80%, P<.001; OS, 5y rates: 12 vs 42%, P<.001). However, the outcome of pts with fav AML harboring MDS-related mut was worse than outcome of pts with fav AML without MDS-related mut (CR, 80 vs 93%, P=.002; OS, 5y rates, 42 vs 53%, P=.009, Fig. B) thus challenging this new hierarchical assignment. 2) We also found that NPM1-mutated pts with adv cytogenetic abnormalities, whom 2022 ELN assigns to the adv group, had similar CR rates (84 vs 79%, P=.99) but better OS (5y rates, 31 vs 14%, P<.001) than pts harboring NPM1 mut and FLT3-ITD, who are classified in the int group. 3) AML with FLT3-ITD is now categorized in the int group, irrespective of the allelic ratio or concurrent presence of NPM1 mut. However, OS of pts with FLT3-ITD was worse than OS of pts without FLT3-ITD remaining in the int group (5y rates: 19 vs 37%, P<.001). 4) Lastly, the 2022 ELN now require only an in-frame bZIP CEBPA mut for classification into the fav group. Indeed, CR rates and OS of bZIP CEBPA-mutated pts were superior to those of pts with non-bZIP CEBPA mut or CEBPA wild-type. Conclusions: The 2022 ELN genetic-risk classification made changes that acknowledge advances in our understanding of disease biology and AML-associated gene mut. This classification provides guidance for risk stratification with similar efficacy as the previous, 2017 one. Our analyses both confirm and challenge the prognostic relevance of some of the newly added features. U10CA180821, U10CA180882, U24CA196171; Clinicaltrials.gov Ids: NCT00048958 NCT00899223, NCT00900224; https://acknowledgments.alliancefound.org Shared authorship, first: KM, JK; last: JCB, A-KE Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Parallel Detection of Single-Cells and Extracellular Vesicles from Bone Marrow and Peripheral Blood Reveals Asymmetric Immunometabolic Profile in Acute Myeloid Leukemia

Introduction. Acute myeloid leukemia (AML) is an aggressive disease with a high relapse rate. Alteration in cell metabolism and metabolic adaptation are crucial hallmarks in AML. Although several studies have addressed the metabolic profile of leukemic cells, the metabolic cross-modulation of immune cells according to their resident (bone marrow, BM) and circulating (peripheral blood, PB) status has been poorly investigated. Growing evidence has highlighted a key role for extracellular vesicles (EVs), shed from a broad variety of cells and cargo of crucial factors, in modulating several functions of leukemic cells, including bioenergetic metabolism. Again, few studies have addressed the impact of EVs in regulating the metabolism of immune cells from leukemic microenvironment. Therefore, in our work, we dissected the immunometabolic profile of immune cells and EV signature profile in parallel from BM versus PB from AML patients. Methods. BM/PB samples and plasma were collected from AML patients at diagnosis (n=40). Leukemic EVs (herein referred to as AML EVs) were purified from platelet-poor plasma BM/PB by size exclusion chromatography and ultrafiltration. MACSPlex Exosome Kit was used for screening surface EV markers. Flow cytometry-based Single Cell ENergetic metabolism by profilIng Translation inhibition (SCENITH) method was applied in fresh whole blood. In addition, BM/PB mononuclear cells from AML patients were characterized by SCENITH after co-culture with circulating AML EVs. Results. To explore the metabolic reprogramming within the leukemic immune microenvironment, we firstly applied the SCENITH method in multiple immune cell subpopulations from AML patients. In comparison with the paired PB, we observed a significant increase in glucose dependence of AML BM CD8+ T cells. By contrast, the capacity to use fatty acids and amino acids as sources for ATP production when glucose oxidation is inhibited was prominently reduced in AML BM CD8+ T cells and increased in AML PB CD8+ T cells. Also, mitochondrial dependence of CD8+ T cells was higher in the BM compartment, suggesting a switch from oxidative phosphorylation to glycolysis in circulation. Interestingly, in comparison to paired PB, only BM CD3+ and CD4+ T cells from female AML patients revealed a marked increase in their glucose dependence reporting gender-dependent metabolic differences. Towards clinically relevant implication, according to European LeukemiaNet (ELN) 2017 risk classification, SCENITH analysis showed a critical reduction in mitochondrial dependence at the expense of glycolytic capacity in circulating CD4+ T cells from favorable-risk AML compared to intermediate/adverse-risk patients. Given the immunometabolic profile between BM and PB cell compartments, we hypothesized that EVs may differentially contribute to immunometabolism according to their BM versus PB localization. Preliminarily, we explored the immune profiling of plasma-derived EVs from AML BM versus PB. We found that BM EVs exhibited higher expressions of specific markers including CD4, CD40, ROR-1 and HLA-II/-ABC compared to PB equivalents. Of note, we observed a novel link between metabolic regulation and EV profiling. Indeed, the glucose dependence of PB CD8+ T cells was negatively correlated to the expression of CD133-1 (stem cell marker) and CD209 (dendritic marker) depicted on circulating (PB) EVs. Finally, we co-cultured AML circulating EVs with BM/PB mononuclear cells from AML patients in pairs to investigate the EV's role in metabolic regulation. Notably, BM CD8+ T cells in monocultures showed a reduction in glucose dependence compared to their PB equivalents. In parallel, mitochondrial dependence was more pronounced in PB CD4+ T cells compared to other circulating immune subsets. However, PB EVs caused a metabolic shift in the PB compartment towards high glycolytic capacity in CD8+ T cells and high mitochondrial dependency in CD34+ cells suggesting an EV-driven metabolic rewiring. Apparently, the co-cultures with PB EVs did not influence the energy profile of resident (BM) immune subsets. Conclusions. Overall, this study shows the immunometabolic asymmetry orchestrated in AML at diagnosis, driven by distinct immune cell subsets according to their location (BM versus PB). We also describe the putative role of AML EVs in subverting the immune cell metabolism revealing critical implications for immunotherapy in AML.

Outcome of autologous stem cell transplantation in patients with favorable-risk acute myeloid leukemia in first remission

ObjectiveTo evaluate the efficacy of autologous hematopoietic stem cell transplantation (auto-HSCT) in patients with favorable-risk acute myeloid leukemia in first remission.MethodTwenty patients who received auto-HSCT at our center between January 2014 and January 2021 were retrospectively reviewed.ResultsUntil last follow-up, three patients in the cohort were dead due to relapse. The estimated 1-year and 5-year overall survival were 95.00% ± 4.87% and 83.82% ± 8.58%, respectively. The estimated 5-year RFS and CIR (cumulative incidence of relapse) were 85.00% ± 7.98% and 15.00% ±7.98%, respectively.ConclusionThe outcome of auto-HSCT in patients with favorable-risk acute myeloid leukemia in first remission was excellent and auto-HSCT could be an effective treatment for these patients.

Intensified cytarabine dose during consolidation in adult AML patients under 65 years is not associated with survival benefit: real-world data from the German SAL-AML registry

PurposeHigher doses of cytarabine appear to improve long-term outcome in acute myeloid leukemia (AML), in particular for younger patients. To this end, the optimal dosage of single-agent cytarabine in consolidation therapy remains elusive. Here, we assessed the impact of different dosages of cytarabine consolidation after 7 + 3 induction on outcome in a large real-world data set from the German Study Alliance Leukemia-Acute Myeloid Leukemia (SAL-AML) registry.MethodsPatients between 18 and 64 years of age, registered between April 2005 and September 2020, who attained complete remission after intensive induction and received at least one consolidation cycle with intermediate (IDAC) or high-dose cytarabine (HiDAC) were selected. To account for differences in patient and disease characteristics between both groups, the average treatment effect was estimated by propensity score weighting.ResultsSix-hundred-forty-two patients received HiDAC consolidation with median dosage of 17.6 (IQR (interquartile range), 16.5–18.0) g/m2 for a median number of 3 cycles (IQR, 2–3), whereas 178 patients received IDAC consolidation with 5.9 (IQR, 5.7–8.6) g/m2 for a median of 2 cycles (IQR, 1–3). Both groups differed significantly in some important characteristics (age, sex, cytogenetic risk group, ECOG performance status, disease status, HCT-CI, number of induction cycles). After propensity score weighting for differences in patient and disease characteristics, relapse-free survival after 2 years was comparable between HiDAC-treated (55.3%) and IDAC-treated (55.6%) patients (HR = 0.935, p = 0.69). Moreover, no significant differences in overall survival were observed after 2 years (84.7 vs. 80.6%, HR = 1.101, p = 0.65). Notably, more patients treated with IDAC received allogeneic hematopoietic cell transplantation in first remission (37.6 vs. 19.8%, p < 0.001). Censoring for allogeneic hematopoietic cell transplantation in first remission revealed no significant survival difference with regard to cytarabine dosage. Considering only of European LeukemiaNet (ELN) favorable-risk AML patients, there was no significant difference in outcome. Of note, significantly more patients treated with HiDAC suffered from ≥ 3 CTCAE infectious complications (56.7 [95%-CI 52.8–60.6%] vs. 44.1% [95%-CI 36.6–51.7%]; p = 0,004). The rate of other ≥ 3 CTCAE non-hematological toxicities and secondary malignancies was comparable in both treatment groups.ConclusionsThis retrospective analysis suggests no significant benefit of high-dose cytarabine compared to intermediate dosages in consolidation for AML patients under 65 years of age, independent of ELN risk group.Trial registrationNCT03188874.

Germline and Somatic Defects in DDX41 and its Impact on Myeloid Neoplasms.

While DDX41 mutation (m) is one of the most prevalent predisposition genes in adult myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML), most patients do not always present with a family history of MDS/AML. In this review, we will be highlighting epidemiological data on DDX41m, roles of DDX41 in oncogenesis, mechanisms of clonal evolution with somatic DDX41m, and clinical phenotypes and management of MDS/AML in patients harboring DDX41m. DDX41 encodes a DEAD-box helicase protein that is considered essential for cell growth and viability. High incidence of myeloid malignancies and other cancers in patients bearing DDX41m suggests that defects in DDX41 lead to loss of a tumor suppressor function, likely related to activities in RNA splicing and processing pathways. Seventy percent of cancer cases with DDX41m are associated with MDS/AML alone. More than 65% of familial cases harbor heterozygous germline frameshift mutations, of which p.D140Gfs*2 is the most common. A somatic DDX41m of the second allele is acquired in 70% of cases, leading to hematological malignancy. Myeloid neoplasms with DDX41m are typically characterized by long latency, high-risk disease at presentation with normal cytogenetics and without any additional molecular markers. Recent reports suggests that a subgroup of these patients have an indolent clinical course and have a better long-term survival compared to favorable or intermediate risk AML. Distinct clinical/pathologic features and favorable outcomes in MDS/AML highlight the need for standardized classification and gene specific guidelines that could assist in management decisions in patients with DDX41m.

P526: REAL-WORLD COMPARISON OF DIFFERENT TREATMENT MODALITIES FOR FAVORABLE RISK ACUTE MYELOID LEUKEMIA: STANDARD DOSE ANTHRACYCLINE VS HIGH DOSE ANTHRACYCLINE VS ADDITION OF GEMTUZUMAB OZOGAMICIN

Background: The standard remission induction regimen for medically fit patients with acute myeloid leukemia (AML) consists of a backbone of cytarabine & an anthracycline (“7 + 3” therapy). However, the choice & dose of the anthracycline varies between institutions & practitioner preference, particularly in AML with favorable risk cytogenetics. Gemtuzumab ozogamicin (GO) may improve outcomes in this patient population but is associated with increased toxicities. Aims: We aimed to compare the outcomes of 3 cohorts of newly diagnosed AML with favorable cytogenetics who received induction 7 + 3 induction therapy: 1. Standard dose (45 or 60 mg/m2 daunorubicin) (SD); 2. Higher dose (90 mg/m2 daunorubicin or 12 mg/m2 idarubicin) (HD) of anthracycline, 3. 7 + 3 with fractionated GO. Methods: We performed a multicenter retrospective analysis of medically fit patients ≥ 18 yo with favorable risk AML determined using ELN 2017 guidelines from 2015-2020 treated across 6 US academic institutions. Categorical variables were summarized using means and standard deviations. The former was compared using Fisher’s exact test; the latter was compared using either the Wilcoxon text or the Kruskal-Wallis as appropriate. One way ANOVA test was used to compare continuous variables. Kaplan-Meier curves were generated to provide visual summaries of survival and time-to-event data. Results: Our study included 189 treated patients who met eligibility criteria with a median follow up of 2 years. Patients’ characteristics and outcomes are summarized in Table 1. Sixty-nine (37%) received induction with SD, 100 (53%) received HD, and 20 (11%) received GO. Patients in the SD and HD group were younger (median age 50 and 52 yo, respectively) and the majority (>94%) had de novo AML. The rates of composite complete remission in the SD, HD, and GO groups were 66.7%, 70% and 75%, respectively (p=0.761). RFS and OS were similar between all groups (p=0.4 and 0.3, respectively). The rate and duration of cytopenias at day 40 after induction, major bleeding, infections, admission to the intensive care unit, new onset cardiomyopathy (ejection fraction<50%), liver dysfunction and acute renal injury were similar among all groups. No patients developed veno-occlusive disease. Table 1: - Participant Characteristics and Outcomes by Treatment Regimen GON = 20 HDN = 100 SDN = 69 P-value Age in years (standard deviation) 57.75 (9.32) 49.68 (13.67) 51.55 (13.83) 0.038 de novo AML, N (%) 19 (95.0) 94 (94.0) 65 (94.2) 1.000 Disease status after induction 0.812 CR, N (%) 14 (70.0) 66 (66.0) 40 (58.0) CRi, N (%) 0 (0.0) 2 (2.0) 2 (2.9) Persistent, N (%) 1 (5.0) 4 (4.0) 2 (2.9) Composite CR, N (%) 15 (75.0) 70 (70.0) 46 (66.7) 0.761 Admission to ICU, N (%) 4 (20.0) 17 (17.0) 11 (15.9) 0.969 Infections, N (%) 17 (85.0) 74 (74.0) 62 (89.9) 0.082 Major bleeding, N (%) 3 (15.0) 6 (6.0) 4 (5.8) 0.299 VOD, N (%) 0 (0.0) 0 (0.0) 0 (0.0) Transaminitis, N (%) 4 (20.0) 19 (19.0) 19 (27.5) 0.538 Acute renal injury, N (%) 3 (15.0) 19 (19.0) 15 (21.7) 0.962 Cardiomyopathy, N (%) 4 (20.0) 8 (8.0) 5 (7.2) 0.523 Cytopenias at D40 after induction, N (%) 0 (0.0) 7 (7.0) 6 (8.7) 0.542 Image:Summary/Conclusion: Our analysis demonstrated no differences in RFS and OS in patients with AML treated with either GO, HD or SD. In addition, the rates of complications secondary to chemotherapy were similar among all groups. However, a measurable residual disease analysis is ongoing for further characterization of disease response.

Comparison of different treatment modalities for favorable risk acute myeloid leukemia: Standard-dose anthracycline versus high-dose anthracycline versus addition of gemtuzumab ozogamicin.

e19016 Background: The standard remission induction regimen for medically fit patients with AML consists of a backbone of cytarabine &amp; an anthracycline (“7+3” therapy). However, the choice &amp; dose of the anthracycline varies between institutions &amp; practitioner preference, particularly in patients with favorable risk cytogenetics. Gemtuzumab ozogamicin (GO) may improve outcomes in this patient population but is associated with increased toxicities. Methods: We performed a retrospective analysis on medically fit patients ≥ 18 yo with favorable risk AML from 2015-2020 treated with 7+3 at the University of Virginia. Patients were stratified based on standard dose (45 or 60 mg/m2 daunorubicin) (SD) vs higher dose (90 mg/m2 daunorubicin or 12 mg/m2 idarubicin) (HD) of anthracycline vs the addition of GO. Measures included rates of remission, EFS, RFS, and OS as well as rates of treatment-related complications. Results: In total, 58 patients were identified, of which 33 received induction with SD, 19 received HD, &amp; 6 received GO. The majority (75%) of patients were &lt; 60 years old &amp; 93% had de novo AML. The rates of complete remission in the SD, HD &amp; GO groups were 90.9%, 89.5% &amp; 100%, respectively (p = 0.57). EFS at 2-years was 43.9%, 36.7%, &amp; 66.7%, respectively (p = 0.85). RFS at 2-years was 53.0%, 39.0%, &amp; 100%, respectively (p = 0.18). OS at 2-years was similar between all groups (58.9%, 56.9%, &amp; 66.7%, p = 0.92). The rate &amp; duration of cytopenias after induction were similar among all groups (median duration 29 days), however cytopenias were more common in the GO group following consolidation. The rates of major bleeding, admission to the intensive care unit (ICU), and new onset cardiomyopathy (EF &lt; 50%) were higher in the GO group (major bleeding: 0% in SD, 5.3% in HD, 33.3% in GO; ICU admission: 12.1% in SD, 21.1% in HD, 33.3% in GO; cardiomyopathy: 12.1% in SD, 26.3% in HD, 33.3% in GO). The rate of infection, liver dysfunction, &amp; acute renal injury were similar among all groups. No patients developed veno-occlusive disease. Conclusions: Patients receiving GO had a trend toward improved EFS &amp; RFS, however with a similar OS at the expense of higher rates of cytopenias, major bleeding, ICU admission, &amp; cardiotoxicity. Patients receiving HD had a trend toward worse outcomes than those who received SD. A major limitation of our study is the small sample size &amp; single institution experience, however multi-institutional analysis is ongoing for further investigation.[Table: see text]