European LeukemiaNet Classification Research Articles

Genetic risk stratification and outcomes among treatment-naive patients with AML treated with venetoclax and azacitidine

AbstractThe European LeukemiaNet (ELN) acute myeloid leukemia (AML) genetic risk classification systems are based on response to intensive chemotherapy; their ability to discriminate outcomes in older patients treated with venetoclax-azacitidine may be suboptimal. This pooled analysis of the phase 3 VIALE-A trial (NCT02993523) and phase 1b study (NCT02203773) examined prognostic stratification according to the 2017 and 2022 ELN risk classifications and derived new molecular signatures differentiating venetoclax-azacitidine–treated patients based on overall survival (OS). Overall, 279 patients treated with venetoclax-azacitidine and 113 patients treated with placebo-azacitidine were analyzed. The ELN 2017 or 2022 prognostic criteria classified most patients as adverse-risk AML (60.2% and 72.8% for venetoclax-azacitidine and 65.5% and 75.2% for placebo-azacitidine, respectively). Although outcomes with venetoclax-azacitidine improved across all ELN risk groups compared with placebo-azacitidine, ELN classification systems poorly discriminated venetoclax-azacitidine outcomes. By applying a bioinformatic algorithm, new molecular signatures were derived differentiating OS outcomes with venetoclax-azacitidine. The mutational status of TP53, FLT3 internal tandem duplication (FLT3-ITD), NRAS, and KRAS categorized patients into higher-, intermediate-, and lower-benefit groups (52%, 25%, and 23% of patients, respectively), each associated with a distinct median OS (26.5 months [95% confidence interval (CI), 20.2-32.7]; 12.1 months [95% CI, 7.3-15.2]; and 5.5 months [95% CI, 2.8-7.6], respectively). ELN prognostic classifiers did not provide clinically meaningful risk stratification of OS outcomes in patients treated with venetoclax-azacitidine. TP53, FLT3-ITD, NRAS, and KRAS mutation status allows the classification of these patients into 3 risk groups with distinct differences in median OS. These trials were registered at www.clinicaltrials.gov as #NCT02993523 and #NCT02203773.

Low frequency of Vγ9Vδ2 T cells predicts poor survival in newly diagnosed acute myeloid leukemia

AbstractIn several tumor subtypes, an increased infiltration of Vγ9Vδ2 T cells has been shown to have the highest prognostic value compared with other immune subsets. In acute myeloid leukemia (AML), similar findings have been based solely on the inference of transcriptomic data and have not been assessed with respect to confounding factors. This study aimed at determining, by immunophenotypic analysis (flow or mass cytometry) of peripheral blood from patients with AML at diagnosis, the prognostic impact of Vγ9Vδ2 T-cell frequency. This was adjusted for potential confounders (age at diagnosis, disease status, European LeukemiaNet classification, leukocytosis, and allogeneic hematopoietic stem cell transplantation as a time-dependent covariate). The cohort was composed of 198 patients with newly diagnosed (ND) AML. By univariate analysis, patients with lower Vγ9Vδ2 T cells at diagnosis had significantly lower 5-year overall and relapse-free survivals. These results were confirmed in multivariate analysis (hazard ratio [HR], 1.55 [95% confidence interval (CI), 1.04-2.30]; P = .030 and HR, 1.64 [95% CI, 1.06-2.53]; P = .025). Immunophenotypic alterations observed in patients with lower Vγ9Vδ2 T cells included a loss of some cytotoxic Vγ9Vδ2 T-cell subsets and a decreased expression of butyrophilin 3A on the surface of blasts. Samples expanded regardless of their Vγ9Vδ2 T-cell levels and displayed similar effector functions in vitro. This study confirms the prognostic value of elevated Vγ9Vδ2 T cells among lymphocytes in patients with ND AML. These results provide a strong rationale to consider consolidation protocols aiming at enhancing Vγ9Vδ2 T-cell responses.

Complex karyotype but not other cytogenetic abnormalities is associated with worse posttransplant survival of patients with nucleophosmin 1-mutated acute myeloid leukemia: A study from the European Society for Blood and Marrow Transplantation Acute Leukemia Working Party.

In the 2022 European LeukemiaNet classification, patients with nucleophosmin 1 (NPM1)-mutated acute myeloid leukemia (AML) were classified in the adverse-risk category in the presence of high-risk cytogenetics (CG). Nonetheless, the impact of various CG aberrations on posttransplant outcomes remains to be unraveled. This registry study analyzed adult patients with NPM1-mutated de novo AML who underwent their first allogeneic hematopoietic cell transplantation in the first complete remission from 2005 to 2021. A total of 3275 patients were identified, 2782 had normal karyotype, 493 had chromosomal aberrations including 160 with adverse-risk CG, 72 patients had complex karyotype (CK), and 66 monosomal karyotype (MK). Overall, 2377 (73%) patients had FLT3-ITD. On univariate analysis, only FLT3-ITD, minimal/measurable residual disease (MRD) positivity and CK, but not abnormal CG, affected posttransplant outcomes. On multivariable analysis, CK was associated with lower overall survival (OS) (hazard ratio [HR] 1.72, p = .009). In the subgroup of 493 patients with aberrant CG, the 2-year leukemia-free survival (LFS) and OS were around 61% and 68%, respectively. On multivariable analysis for this subgroup, CK and MRD positivity were associated with increased risk of relapse (HR 1.7, p = .025; and 1.99, p = .003 respectively) and worse LFS (HR 1.62, p = .018; and 1.64, p = .011 respectively) while FLT3-ITD, MK, or other CG abnormalities had no significant effect. Importantly, CK negatively affected OS (HR 1.91, p = .002). In the first complete remission transplant setting, CK was found as the only cytogenetic risk factor for worse outcomes in NPM1-mutated AML. Nevertheless, even for this subgroup, a significant proportion of patients can achieve long-term posttransplant survival.

Encouraging Outcome of AML with t(8;16) Following Allogeneic Stem Cell Transplantation in First Remission - a Retrospective Analysis on Behalf of the Acute Leukemia Working Party of the EBMT

In the 2022 European Leukemia Net (ELN) risk classification, acute myeloid leukemia (AML) with translocation t(8;16) was newly classified as AML defined by specific cytogenetic abnormalities, associated with unfavorable prognosis. Translocation (8;16)(p11;p13) is a rare abnormality in AML with female preponderance and occurs more frequently in secondary AML (sAML), especially therapy-related, than in de novo disease. Clinically, AML with t(8;16) is associated with high risk of bleeding, occurrence of extramedullary manifestations, myelomonocytic differentiation, and signs of hemophagocytosis in the bone marrow. The translocation leads to the fusion of acetyltransferase KAT6A (also known as MOZ or MYST3) and CREB binding protein ( CREBBP) genes, both of them involved in hematopoiesis. ELN risk stratification of AML with t(8;16) was based on studies that included relatively low numbers of patients receiving allogeneic stem cell transplantation (alloSCT). In the largest report by Kayser et al. ( Br J Haematol 2021) 21 patients (15 transplanted in first complete remission [CR1], median follow-up 5.5 years) were analyzed. A 5-year overall survival (OS) of 38% was achieved after alloSCT compared to 11% in patients who received chemotherapy only. The aim of our study was to evaluate the outcome of patients with AML harboring t(8;16) after alloSCT in a larger cohort from the EBMT registry. All types of donor, conditioning regimen and graft were included. Sixty patients were identified, of whom 44 had been transplanted in CR1. Median follow-up from alloSCT was 72.3 months, median age was 46.3 years, and 73.3% were female. Karnofsky performance status was >80% in 59 patients, one had missing data. At 2 years after alloSCT, OS and leukemia free survival (LFS) of the entire cohort were 42.7% and 42.2%, respectively, (28.6% and 14.3% in patients transplanted in advanced disease). Cumulative incidence of relapse (RI) and non-relapse mortality (NRM) at two years was 36.9% and 15.3%, respectively, in patients transplanted in CR1, and 78.6% and 7.1%, respectively, in patients transplanted in advanced disease. The 44 patients transplanted in CR1 were analyzed in detail. Basic characteristics were comparable to the entire cohort as described above. Twenty-two of the patients had de novo, 22 had sAML. According to the ELN 2017 classification (not yet including t(8;16) as a factor for poor prognosis), 54.5% had an intermediate and 45.5% an adverse cytogenetic risk. Furthermore, 38.8% had a complex karyotype. Donors were matched related in 34%, matched unrelated in 54%, haploidentical in 5% and cord blood in 7%. Conditioning was myeloablative in 52.3%, whereas 47.7% had received reduced intensity conditioning. Among patients transplanted in CR1, 2- and 5-year OS from alloSCT was 48% and 39.9%, the respective LFS was 46.8% and 35.5%. On multivariate analysis (MVA), harboring t(8;16) within a complex karyotype was the major risk factor for outcome, being associated with higher RI (hazard ratio [HR] 3.38, p=0.01), lower LFS (HR 4.17, p=0.016), and lower OS (HR 3.08, p=0.017). In contrast, patients with t(8;16) outside of a complex karyotype achieved excellent results (Figure 1). Besides a complex karyotype, MVA revealed sAML as an additional, independent risk factor with a higher RI (HR 3.73, p=0.026). Age was the major factor for NRM, reaching 5% vs. 26.5% in patients below or above the median (p=0.02). In conclusion, according to the largest series analyzed in this setting so far, overall results after alloSCT in AML with t(8;16) transplanted in CR1 were favorable, especially in patients without multiple additional cytogenetic abnormalities, achieving a low risk of relapse and a 5-year OS >60%. Hence, alloSCT in CR1 appears to abrogate the unfavorable prognostic value of this translocation. Whether or not t(8;16) does have any additional influence on the outcome of patients with a complex karyotype remains to be evaluated. Figure Legend Figure 1: Outcome of AML with t(8;16) with and without complex karyotype

Comparison of Two Venetoclax-Based Regimens As Salvage Therapies Bridged to Allogeneic Hematopoietic Cell Transplantation in Patients with Relapsed/Refractory Acute Myeloid Leukemia

Introduction ： Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective treatment for relapsed or refractory acute myeloid leukemia (R/R-AML) patients. However, it is not clear about appropriate salvage therapy bridged to allo-HSCT for R/R-AML patients. In this study, we compared the outcomes of R/R-AML patients treated with venetoclax plus hypomethylating agents (VEN-HMA) regimen or venetoclax plus azacitidine and homoharringtonine (VAH) regimen as salvage therapies bridged to allo-HSCT. Methods ： A total of 105 R/R-AML patients treated with VEN-HMA regimen or VAH regimen bridged to allo-HSCT between September 2018 and February 2023 were enrolled. The outcomes including survival, relapse and NRM after allo-HSCT were analyzed in two groups. Results ： Forty-four patients were treated with VEN-HMA regimen, and 61 with VAH regimen. Seventy-four patients had primary refractory AML and 31 relapsed AML, including 19 relapsed after chemotherapy and 12 relapsed after allo-HSCT. Thirty-one (70.5%) patients achieved composite complete remission (CRc) in VEN-HMA group including 20 (45.5%) with minimal residual disease (MRD) negative, as well as 52 (85.2%) with CRc including 40 (65.6%) with MRD negative in VAH group (P=0.09). Twenty-five (56.8%) patients were stratified with adverse risk in VEN-HMA group and 45 (73.8%) in VAH group according to the 2022 European Leukemia Net (ELN) classification (P=0.07). The 2-year overall survival (OS) and event-free survival (EFS) in VAH group were higher (78.4% vs 58.7%, P=0.03; 68.3% vs 38.7%, P=0.003), as well as 2-year cumulative incidence of relapse (CIR) was lower than VEN-HMA group (23.2% vs 42.4%, P=0.04). Among patients with CRc, the 2-year OS, EFS and CIR was 67.5%, 48.9% and 37.0% in VEN-HMA group, as well as 82.5%, 72.5% and 23.6% in VAH group (P=0.15, 0.05 and 0.24). Among patients with MRD negative, the 2-year OS, EFS and CIR was 75.5%, 55.5% and 31.6% in VEN-HMA group, as well as 90.8%, 80.0% and 17.5% in VAH group (P=0.15, 0.10 and 0.28). Among patients with adverse risk, the 2-year OS and EFS in VAH group were higher (79.3% vs 47.7%, P=0.01; 70.9% vs 24.1%, P=0.0002), as well as 2-year CIR was lower than VEN-HMA group (17.4% vs 45.8%, P=0.01). Non-relapse mortality (NRM) was similar between VEN-HMA group and VAH group (18.9% vs 8.5%, P=0.12). Conclusion ： VAH regimen is an effective salvage therapy bridged to allo-HSCT for R/R-AML patients compared with VEN-HMA regimen. Keywords ： Venetoclax, Azacitidine, Homoharringtonine, Relapsed/Refractory AML, Allogeneic Hematopoietic Cell Transplantation.

Real-World Study in Acute Leukemia: Epidemiology, Treatment Patterns and Outcomes for Newly Diagnosed AML in Adult Patients from Latin America - Loyal Study

Introduction. Acute myeloid leukemia (AML) is the most frequent leukemia among adults and representing 90% of all cases of acute leukemia in adults. Differences in incidence and burden of AML among regions of the world have been reported. When compared with registries from the US, UK and Sweden, Latin-America (LA) AML has a younger age at diagnosis (median age of 40-47 versus 64 -67 years old). Furthermore, single center studies have suggested poor treatment outcomes in LA. For example, Silveira et al reported a median age at diagnosis of 46 y, frequency of favorable cytogenetics of 26% and median overall survival (mOS) of 12 months in the Brazilian cohort of patients with newly diagnosed AML (nAML) whereas the respective values at Oxford University were 51.5y, 11% and 48 months in British patients. However, wider studies across the region are scarce and there is a need to further explore AML patient characteristics and treatment outcomes in LA. Methods. This is a non-interventional, retrospective multicenter study that aims to describe the epidemiology, clinical and demographic characteristics, treatment patterns, survival outcomes and healthcare resource use of adult patients with nAML in Argentina, Brazil, Chile, and Colombia. Data from medical records of eligible patients that met the inclusion criteria (≥ 18 years old at diagnosis, confirmed diagnosis of nAML between 01 January 2015 and 31 December 2019, and receiving at least one line of treatment) in these LA countries were considered for the analysis, which was descriptive in nature as no hypothesis has been tested. Results: A total of 518 nAML patients were included in the study, 166 from Argentina, 205 from Brazil, 63 from Chile, and 84 from Colombia. Table 1 shows the demographics and clinical characteristics. At treatment initiation, an evaluation of fitness (eligibility) for intensive chemotherapy was available for 94% of the patients (n=489). The majority were considered fit (75.5%; n=391) and received standard 7+3 therapy. About 11% of patients (n=9) were refractory to induction therapy. Median OS for fit patients was 11.9 months, whereas for unfit patients was 5.8 months. Mutational status of genes listed by the European LeukemiaNet (ELN) Classification of 2017 was not available for the majority of cases; risk categories were assigned based on cytogenetics. Patients in the favorable-risk category had a mOS of 30.5 months, whereas those in the intermediate- and unfavorable-risk had 11.1 and 9.1 months, respectively (Figure 1). The probability of 5year OS rates for favorable, intermediate- and unfavorable-risk groups were of 38.8%, 16.6% and 20.9%, respectively. Eighty-six patients (17%) discontinued treatment with reasons being adverse event/toxicity (33%; n=28), death (32%; n=27), and disease progression (17%; n=14). Only 24% of patients (n=125) underwent a subsequent stem cell transplantation (SCT), mainly allogenic (98%; n=121). For SCTs, identical (matched) related (50%; n= 59) and haploidentical donor (35%; n=41) were the most common. Patients not eligible to intensive chemotherapy were treated with HMA (9%; n=47) and LDAC (5%; n=25), with 10% of the patients receiving palliative/supportive care. The most common treatment protocols used in relapsed or refractory (R/R) patients were high-dose cytarabine (HDAC) (31%; n=85), followed by FLAG-IDA (24%; n=66). Conclusions: This study of newly diagnosed acute leukemia characterizes real-world treatment patterns and outcomes in LA clinical practices. Prior to this study, there has been limited published data on the epidemiology and treatment patterns across LA. This study highlights that for nAML patients, the most common treatment in LA is 7+3 and most patients are classified as fit. The vast majority of patients had their risk accessed by cytogenetics analysis only, reflecting the limited access to molecular tests. Fewer patients underwent stem cell transplantation as part of the treatment compared to that reported in US and Europe, probably due to restricted availability of hospital beds dedicated to bone marrow transplantation. When evaluating the overall survival, the study shows higher mOS for favorable risk. In addition, mOS for intermediate and poor cytogenetic risk were similar. A broader access in the region to molecular tests, transplant and new therapies are needed in order to reduce the gap in outcome, especially for patients with intermediate-risk.

A High Percentage of DNAM-1+ and Low Percentage of Tactile+ NK Cells at Diagnosis Correlate with Complete Response and Survival in AML: A Sub-Analysis of the Ven-a-Qui Pethema Trial

Background: Natural killer (NK) immune status in Acute Myeloid Leukemia (AML) could influence therapeutic results and natural history of the disease. Objectives: In the phase I/II VEN-A-QUI (Clinical trials NCT04687761) clinical trial for unfit newly diagnosed AML patients (venetoclax+Quizartinib+azacytidine or low-dose cytarabine), it was planned a prospective study of NK populations and their influence in the main clinical outcomes. NK cells were analyzed at the diagnosis in a central laboratory. Material and methods: We analyzed NK cell subpopulations based in the expression of DNAM-1, TIGIT, TACTILE, CD8, PD-1, TIM-3, LAG-3, NKp44, NKp46, NKp30, CD16, CD85j,KIR2D, NKG2C, NKG2A, CD57, CD6, CD244, NKp80, Perforin, Granulolysin and Granzyme B. We compare composite Complete Remission (CRc) results of the Venetoclax/Quizatinib with Aza or Cytarabine vs. not achieving CRc using t Student. MaxStat statistics was used to test the significant limit of those populations with a significant difference (R-statistics version 4.2.2). Survival analysis comparing significant differences between patients in CRc was performed using LogRank test and Kaplan Maier. Cox survival analysis was performed to evaluate if the presence of this populations could be an independent factor against the European Leukemia Net classification of 2017 and p53. Data of molecular characteristics were obtained with an NGS panel of 40 genes. RESULTS: The trial included 76 ineligible patients for intensive chemotherapy (37 and 39 were in Aza and LDAC arms respectively). cCR was obtained in 39 patients (51.3%). ELN2017 risk was favorable in 8, intermediate in 15, and Adverse in 53. In 70 patients NK cell populations were analyzed (4 patients with very low percentage of NK cells, 2 with no sample at diagnosis were excluded from the study). There were significant differences between patients who achieve CRc and those who did not, according to DNAM-1 (74.4% vs 61.9, p=0.0018) and TACTILE (62% vs. 72%, p=0.02) expression on NK cells. The rest of antigens analyzed on NK cells were not significant. We found a cutoff of 62% of DNAM-1+ and less than 81% of TACTILE to differentiate populations in terms of survival using long-rank test. The number of DNAM-1 positive was 47 (60%) and TACTILE- was 55 (78%). The median OS of DNAM-1+ was better than DNAM-1− (18.4 vs 4.7 months, p=0.0001), and between TACTILE− vs TACTILE+ (17,36 vs. 4.6 months, p=0.005). Using an Cox model comparing karyotype, p53 and DNAM-1+ and TACTILE-, only DNAM-1+ was associated with better outcome (HR:0.33 (0.17-0.66) and TACTILE+ with worse (HR: 2.44 (1.20-4.99) in multivariate analysis. Conclusions: DNAM-1(CD226) positive and TACTILE (CD96) negative NK cell populations are associated to CR and better OS. These findings need to be confirmed in larger studies. Interestingly, DNAM-1 is an activating receptor and TACTILE is an inhibitory receptor for NK cells that share the same CD155 ligand but display opposite function.

Optimal Duration of CPX-351 Treatment and Best Timing for Consolidation with Allogeneic Stem Cell Transplantation: Evidence from a Large Real-World Italian Study

Background: CPX-351, has been approved for the treatment of patients diagnosed with Acute Myeloid Leukemia (AML) arising from a previous myelodysplastic syndrome (s-AML) or secondary to chemotherapy (t-AML) as per former WHO 2016 classification, following results from the phase III trial (Lancet et al, JCO2018). Long term results from the trial confirmed that the benefit from CPX-351 over conventional 3+7 induction was maintained both in patients proceeding or not to allogeneic stem cell transplantation consolidation (HSCT). However, the information on the optimal duration of treatment with CPX-351 or the best timing for HSCT consolidation are still incomplete. Furthermore, there is also scarce data on the efficacy of CPX-351 among NPM1 or FLT3-ITD mutated AML or in patient with low risk AML according to European Leukemia Net (ELN) classification, as those subgroups are rare among t-AML and s-AML. Aims: The aim of this study is to analyze the outcome of CPX-351 treatment in a large cohort of patient who received commercially available treatment in Italy since the approval of the drug, in order to identify the optimal duration of treatment, the best timing for HSCT and to evaluate the efficacy among more rare secondary AML subtypes. Methods: 513 elderly (median age 65.6 years, range 19-79) s-AML or t-AML patients who received CPX-351 treatment in 38 Italian Centers since January 2019 were retrospectively included in this study. All patients received CPX-351 as per Italian Drug Authority (AIFA) approval, allowing up to two induction cycles and up to two consolidation. Diagnostic workup was performed as per internal standard in all patients. Eligible patients proceeded to HSCT consolidation as per internal standard of each Center. 108 (21.1%) and 405 (78.9%) patients were diagnosed with t-AML or s-AML, respectively. NPM1 mutation were found in 31 patients (6%), FLT3-ITD mutation was present in 24 patients (4.6%). ELN 2017 score was favorable, intermediate or high in 27 (5.2%), 177 (34.5%) and 309 (60.3%) patients, respectively. Most patients had relevant comorbidities (84%), mainly cardiovascular disease (43%), type II diabetes (39%). After induction 1, 297/513 patients (58%) achieved a complete remission (CR). 72 patients failing to achieve CR received induction 2. After induction 2, CR was achieved in 340/513 patients (66.3%). CR rate was significantly higher among NPM1 mutated patients (p <0.05) and among ELN 2017 favorable risk patients if compared to intermediate or high risk (p<0.05), whereas was not affected by FLT3-ITD mutations. Among responding patients, 118 (34.7%), 137 (40.3%) and 85 (25%) received none, one or two consolidation cycles, respectively. HSCT consolidation in first CR was performed in 166/340 responding patients (48.8%). 30 and 60-days mortality were 5.2 and 8.2%, respectively. After a median follow-up of 23.66 months (CI 95% 23.11 - 26.01), median OS was 16.23 months (CI 95% 13.6 - 18.9). OS was significantly influenced by NPM1 mutational status (p<0.05) and ELN 2017 risk score (p<0.05, Fig. 1A). Of note, NPM1 mutated patients and ELN 2017 low-risk patients showed a very good outcome (Median OS 24.6 months for NPM1 mutated patients and not reached in ELN 2017 favorable risk patients). In a landmark analysis including patients alive and in CR at day 90, HSCT was the strongest predictor of longer survival (Median OS not reached and 16.3 months for patients receiving or not HSCT, respectively, p<0.05). In the same landmark model, completion of all allowed CPX-351 treatment was beneficial only in patients not proceeding to HSCT (median OS 20.36 and 12.2 months in patients receiving 2 or less CPX-351 consolidation without HSCT, respectively, p<0.05, Fig. 1B), whereas in patients receiving HSCT consolidation further CPX-351 treatment after cycle 1 did not improve results (Median OS not reached, 35 and 28.4 months in HSCT patients receiving 0, 1 or 2 CPX-351 consolidations, respectively, p=n.s.) Conclusions: Our large cohort confirms the efficacy of CPX-351 treatment and suggests that CPX-351 may be beneficial also in NPM1 mutated and ELN 2017 favorable risk patients. In eligible patients, HSCT should probably be performed as soon as a CR is achieved, whereas patients not proceeding to HSCT may still have a long survival if two consolidations are administered. In a future perspective, maintenance strategies may further improve the results.

Comparative Study for Haplo, MSD and MUD Allo-Hcts for AML Patients with KMT2A Rearrangement: A Study from the Global Committee and the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Background Acute myeloid leukemia (AML) patients with KMT2A rearrangement (KMT2Ar, except for t(9;11)(p21.3;q23.3)/MLLT3::KMT2A) are classified as adverse risk in the 2022 European LeukemiaNet (ELN) classification. There is uncertainty on their outcome following allogeneic cell transplantation (allo-HCT). We compared, in an European Society for Blood and Marrow Transplantation (EBMT) global multi-center registry-based analysis, outcomes following an allogeneic stem cell transplantation (allo-HCT) with either a matched sibling donor (MSD), matched unrelated donor (MUD) or haploidentical donor (HAPLO). Methods Data from 586 AML patients with KMT2Ar receiving a first allo-HCT in 183 EBMT centers from 2010-2022 were analyzed. All patients achieved first complete remission (CR1) before transplantation. Patients with t(9;11), without details on translocation, receiving mismatched UD (<10/10), umbilical cord blood, or grafts with ex-vivo manipulation were excluded. Univariant analysis and Cox regression models were used. Results KMT2A rearranged AML patients received allo-HCT from 201 MSD, 256 10/10 MUD, and 129 HAPLOs. For KMT2Ar type, t(6;11), t(11;19), t(10;11) or other translocations account for 27.8%, 37.5%, 23.9% and 10.8%, respectively. Peripheral blood was the major graft source (83.2%), and myeloablative conditioning accounted for the majority (60.2%) of all allo-HCTs. Engraftment rates were comparable in the three cohorts (MSD 99.5%, MUD 98.4% and HAPLO 96.9% p=0.17). AML relapse was the major cause of death in each donor cohort. On univariate analysis, HAPLO was associated with a lower 2-year relapse incidence (RI) (MSD 41.1%, MUD 37.2%, HAPLO 20%) but a higher 2-year non-relapse mortality (NRM) (MSD 6.1%, MUD 19.3%, HAPLO 21.3%) compared with MSD and MUD. The 180-day cumulative incidence of grade II-IV acute GVHD (aGVHD) was lower in MSD (18.8%) than in MUD (31.3%) or HAPLO groups (26.5%), respectively. The 2-year leukemia-free survival (LFS), overall survival (OS) and GVHD-free/relapse free survival (GRFS) were comparable among the three cohorts. Lower RI was observed in patients with t(11;19) compared with t(6;11) or t(10;11). Complex karyotype (CK) (at least 3 abnormalities) or monosomal karyotype (MK) were both associated with higher RI compared with those without. In addition, in-vivo T cell depletion was related to lower intensive chronic GVHD (cGVHD) incidence. On multivariate analysis, HAPLO HCT was associated with lower RI (hazard ratio [HR=0.46], 95% CI 0.28-0.77; p<0.01) but higher incidence of NRM (HR=2.36, 95% CI 1.17-4.78; p<0.01) compared with MSD, while HAPLO had no significant impact on LFS, OS and GRFS. MUD HCT was associated with higher incidence of grade II-IV aGVHD (HR=1.82, 95% CI 1.19-2,78; p<0.01), NRM (HR=2.73, 95% CI 1.51-4.94; p<0.01), and lower LFS (HR=1.37, 95% CI 1.03-1.83; p<0.05) compared with MSD (reference). Concerning translocation type, t(11;19) was associated with a lower RI (HR=0.64, 95% CI 0.43-0.94; p=0.022), a better LFS (HR=0.66, 95% CI 0.48-0.91; p=0.012), OS (HR=0.63, 95% CI 0.45-0.89; p=0.008) and GRFS (HR=0.75, 95% CI 0.57-1; p=0.049) compared with t(6;11)(reference). Translocations other than t(6;11), t(11;19) or t(10;11) were related to a lower RI (HR=0.45, 95% CI 0.24-0.87) and better OS (HR=0.57, 95% CI 0.34-0.95) compared to t(6;11). MK was associated with higher RI (HR=1.59, 95% CI 1.04-2.45; p<0.05) and lower LFS (HR=1.47, 95% CI 1.01-2.14; p<0.05). Conclusions For AML patients with KMT2Ar, HAPLO HCT was associated with a lower RI but higher NRM, leading to similar LFS, OS and GRFS compared with MUD and MSD HCTs. In the setting of allo-HCT, t(11;19) seems to be associated with favorable outcomes compared with other KMT2Ar.

Modification of the ELN Classification 2022 Refines Risk Assessment in MDS/AML Patients

Background: The International Consensus Classification (ICC) introduced MDS/AML as a novel myeloid disease entity defined by 10-19% blasts in the absence of AML-defining recurrent genetic abnormalities. MDS/AML patients should be eligible for AML-like treatment approaches in clinical trials. It has recently been shown that the AML-based risk classification according to European Leukemia Net (ELN) 2022 criteria fails in MDS/AML while an MDS-based risk classification according to Molecular International Prognostic Scoring System (IPSS-M) was applicable (Huber S et al. EHA 2023). Our aim was to refine the ELN 2022 criteria based on genome sequencing data to better reflect the outcome in this overlap category of MDS and AML. Methods: Non-therapy-related cases of 403 MDS/AML and 686 AML patients classified according to ICC were included. Bone marrow samples were analyzed by cytomorphology, cytogenetics and targeted NGS panel sequencing (median coverage 1500x). Overall survival (OS) was assessed in all AML patients and in a subcohort of 137 MDS/AML patients (median follow-ups: 5.6 and 10.2 years, respectively) in whom also whole genome sequencing (median coverage 100x) was performed. Results: MDS/AML patients had a median age of 74 years (female/male: 153/250). They were subclassified according to ICC as MDS/AML with mutated TP53 (14%), with myelodysplasia-related (MR) gene mutations (67%) or MR cytogenetic abnormalities (5%), or not otherwise specified (14%). Cytogenetic aberrations were detected in 173/403 (43%) cases including del(5q) (18%), -7/del(7q) (13%), and complex karyotypes (16%). Molecular aberrations were detected in 376/403 (93%) cases with a median number of 3 mutations. Most frequent gene mutations were ASXL1 (40%), TET2 (32%), SRSF2 (32%), and RUNX1 (29%); TP53 was mutated in (14%) (details in Figure 1A). Grouping of the MDS/AML cohort according to the ELN 2022 guidelines showed: no MDS/AML patient fulfilled criteria for the favorable ELN risk group, only 14% were classified as intermediate risk, and the vast majority (86%) as adverse risk. The survival of MDS/AML patients substantially differed from a bona fide AML cohort, in particular for adverse risk (Figure 1B left). To more adequately risk stratify MDS/AML patients, we aimed to modify current ELN criteria. Notably, in multivariate Cox regression analysis in addition to -7/del(7q) (hazard ratio/HR: 5.5) and mutated RUNX1 (HR: 2.2), also mutations in EZH2 (HR: 2.2) and in SF3B1 (HR: 0.3) remained significant prognostic markers for OS (all p<0.05). Following this, we defined three hierarchically defined risk groups for MDS/AML patients i) adverse (criteria: complex karyotype, -7/del(7q), mutation in TP53, RUNX1, EZH2), ii) intermediate (criteria: del(5q), mutation in ASXL1, SRSF2, U2AF1, ZRSR2, BCOR or STAG2) and iii) favorable (criteria: sole SF3B1 mutation or none of the abnormalities defined above). Overall, 149 MDS/AML patients (37%) were re-grouped compared to ELN 2022 categories resulting in 49% adverse, 35% intermediate and 16% favorable cases. Survival analysis revealed strong prognostic separations of the three new MDS/AML risk categories with median OS of 1.3 years for adverse, 3.1 years for intermediate and 8.1 years for favorable (overall p<0.001; Figure 1B right). The general survival prediction within MDS/AML was improved in the modified version compared to the original ELN 2022 (corrected Akaike information criterion using Cox models: 876 for modified vs. 902 for ELN 2022). Of note, the outcome of adverse risk MDS/AML according to the modified ELN was comparable to the OS of adverse risk AML according to the original ELN (median OS: 1.3 vs 0.7 years; p=0.304). Conclusion: ForMDS/AML patients, AML-based risk classification according to ELN 2022 guidelines is not applicable as the vast majority of cases are categorized into the adverse risk group based on mutations in splicing factor genes and other secondary-type mutations. Modification of the ELN risk categories reflects the partly MDS-based biology of the disease and substantially improves the prognostic stratification. Most importantly, patients with adverse outcome potentially benefitting from inclusion into clinical trials for novel substances are identified. The validity of the modified risk classification for MDS/AML patients undergoing specific treatment regimens remains to be confirmed in forthcoming studies.

Improvement in Survival of Patients with FLT3 Mutated Acute Myeloid Leukemia: Results from a Retrospective Canadian Cohort

Introduction: FLT3 internal tandem duplication (ITD) mutations have been historically associated with inferior outcomes in patients with acute myeloid leukemia (AML) and an intermediate risk status as per the European LeukemiaNet (ELN) 2022 guidelines. In 2017, the US FDA granted approval to midostaurin for frontline treatment and a year later, gilteritinib for use in relapsed/refractory (R/R) AML. These agents began to be widely used in our provincial leukemia program in early 2018 as per the label indications. In this study, we compared clinical outcomes for patients with FLT3-ITD mutated AML before and after this change in British Columbia. Methods: We identified patients in our program database diagnosed with FLT3-ITD mutated AML from January 1, 2010 to December 31, 2021. Only patients receiving intensive chemotherapy with cytarabine and anthracycline were included. Patients were divided into two eras: 2010-2017 (era 1) and 2018-2021 (era 2). The two eras were compared in terms of patient characteristics, genetics, rate of complete remission (CR) and CR with incomplete count recovery (CRi), receipt of allogeneic stem cell transplant (alloSCT) and the overall and relapse free survival (OS and RFS). OS was calculated from diagnosis to death from any cause and was not censored at the time of alloSCT. RFS was calculated from CR/CRi to relapse. Patients without an event during the study period were censored at the time of last follow-up. Categorical variables were compared using Chi-square and Fisher exact tests and continuous variable were compared using paired T tests. Kaplan-Meier survival method and log rank test were used to estimate and compare survival. Uni- and multivariate analyses were performed in a Cox proportional regression model and alloSCT was considered as a time dependent covariate. Results: 169 patients were included (era 1=101, era 2=68). The median duration of follow up of the entire cohort was 17 months (range 0.5-148.6 months) and follow-up of surviving patients (n=70) was longer in era 1 vs. era 2 (median 88 months vs. 32 months, p<0.001). The median age of the entire cohort was 60 years (range 26-79 years) and it was comparable in both eras. Most patients had normal cytogenetics (era 1: 76%; era 2: 69%). NPM1 was mutated in 69/101 (68%) and 38/68 (56%) patients in eras 1 and 2 respectively. Due to lack of genetic data for era 1, we did not risk stratify based on the recent ELN classification. The rate of CR/CRi was 58/101 (57%) vs. 40/68 (59%) after induction chemotherapy and 78/101 (77%) vs. 58/67 (87%) (p=0.09) at any time in eras 1 and 2 respectively. AlloSCT was performed in 58% and 72% of patients in the two cohorts. Midostaurin was used in 82% and gilteritinib was used in 26% of era 2 patients in the second era. OS was significantly longer in era 2 (median OS 73 months vs. 11 months, HR (death) 6.2, p=0.012) (Figure). The 2-year OS rate was higher in era 2 (57%) than in era 1 (39%). In patients achieving CR/CRi, median RFS was longer in era 2 (51 vs. 16 months, p=0.43), although this was not statistically significant. In univariate Cox regression analysis the following factors were associated with improved OS: use of midostaurin (HR 0.487, 95% CI 0.304-0.779, p=0.003), diagnosis in era 2 (HR 0.583, 95% CI 0.38-0.895, p=0.014) and receipt of alloSCT (HR 0.346,) 95% CI 0.219-0.545, p<0.001). Other parameters including age, sex, NPM1 status and cytogenetics were not significant. In multivariate analysis including era, midostaurin and alloSCT, only the receipt of alloSCT was associated with significantly improved OS (HR 0.362, 95% CI 0.229 - 0.572, p<0.001) whereas use of midostaurin (HR=0.465, CI 0.207-1.042, p=0.063) and era (HR 1.12, 95% CI 0.538-2.34, p=0.76) were not significant. Conclusions: Our results show thatOS for patients with FLT3-ITD AML has improved in patients diagnosed in a more recent treatment era. Patients diagnosed after 2018 were more frequently treated with AlloSCT and FLT3-inhibitors, which may have resulted in improvements in OS. Our findings support the assignment of FLT3-ITD AML to theintermediate risk category as per the current ELN guidelines. A limitation of this study is the differences in follow-up time between eras, which may influence the event rate between the groups.

Comparison of the 2022 and 2017 European LeukemiaNet risk classifications in a real-life cohort of the PETHEMA group

Next-Generation Sequencing is needed for the accurate genetic risk stratification of acute myeloid leukemia according to European LeukemiaNet (ELN) guidelines. We validated and compared the 2022 ELN risk classification in a real-life cohort of 546 intensively and 379 non-intensively treated patients. Among fit patients, those aged ≥65 years old showed worse OS than younger regardless risk classification. Compared with the 2017 classification, 14.5% of fit patients changed the risk with the 2022 classification, increasing the high-risk group from 44.3% to 51.8%. 3.7% and 0.9% FLT3-ITD mutated patients were removed from the favorable and adverse 2017 categories respectively to 2022 intermediate risk group. We suggest that midostaurin therapy could be a predictor for 3 years OS (85.2% with vs. 54.8% without midostaurin, P = 0.04). Forty-seven (8.6%) patients from the 2017 intermediate group were assigned to the 2022 adverse-risk group as they harbored myelodysplasia (MDS)-related mutations. Patients with one MDS-related mutation did not reach median OS, while patients with ≥2 mutations had 13.6 months median OS (P = 0.002). Patients with TP53 ± complex karyotype or inv(3) had a dismal prognosis (7.1 months median OS). We validate the prognostic utility of the 2022 ELN classification in a real-life setting providing supportive evidences to improve risk stratification guidelines.

Somatic exonic deletions in RUNX1 constitutes a novel recurrent genomic abnormality in acute myeloid leukemia.

In acute myeloid leukemia (AML), somatic mutations (commonly missense, nonsense and frameshift indels) in RUNX1 are associated with a dismal clinical outcome. Inherited RUNX1 mutations cause familial platelet disorder. As approximately 5-10% of germline RUNX1 mutations are large exonic deletions, we hypothesized that such exonic RUNX1 aberrations may also be acquired during the development of AML. Sixty well-characterized AML patients were analyzed with Multiplex Ligation-dependent Probe Amplification (MLPA, n=60), micro-array (n=11) and/or whole genome sequencing (WGS, n=8). In total, 25 (42% of the cohort) RUNX1-aberrant patients (defined by the presence of classical mutations and/or exonic deletions) were identified. Sixteen patients (27%) carried only exonic deletions, 5 (8%) carried classical mutations and 4 (7%) carried both exonic deletions and mutations. No significant difference was observed between patients with classical RUNX1 mutations and RUNX1 exonic deletions in median overall survival (OS, 53.1 vs 38.8 months respectively, p=0.63). When applying the European Leukemia Net (ELN) classification including the RUNX1-aberrant group, 20% of the patients initially stratified as intermediate-risk (5% of the whole cohort) were re-assigned to the high-risk group, which improved the performance of ELN classification regarding OS between intermediate and high-risk group (18.9 vs 9.6 months, p=0.09). Somatic RUNX1 exonic deletions constitute a novel recurrent aberration in AML. Our findings have important clinical implications regarding AML classification, risk-stratification and treatment decision. Moreover, they argue in favor of further investigating such genomic aberrations not only in RUNX1 but also in other genes implicated in cancer biology and management.

Outcome prediction by the 2022 European LeukemiaNet genetic-risk classification for adults with acute myeloid leukemia: an Alliance study

Recently, the European LeukemiaNet (ELN) revised its genetic-risk classification of acute myeloid leukemia (AML). We categorized 1637 adults with AML treated with cytarabine/anthracycline regimens according to the 2022 and 2017 ELN classifications. Compared with the 2017 ELN classification, 2022 favorable group decreased from 40% to 35% and adverse group increased from 37% to 41% of patients. The 2022 genetic-risk groups seemed to accurately reflect treatment outcomes in all patients and patients aged <60 years, but in patients aged ≥60 years, relapse rates, disease-free (DFS) and overall (OS) survival were not significantly different between intermediate and adverse groups. In younger African-American patients, DFS and OS did not differ between intermediate-risk and adverse-risk patients nor did DFS between favorable and intermediate groups. In Hispanic patients, DFS and OS did not differ between favorable and intermediate groups. Outcome prediction abilities of 2022 and 2017 ELN classifications were similar. Among favorable-risk patients, myelodysplasia-related mutations did not affect patients with CEBPAbZIP mutations or core-binding factor AML, but changed risk assignment of NPM1-mutated/FLT3-ITD-negative patients to intermediate. NPM1-mutated patients with adverse-risk cytogenetic abnormalities were closer prognostically to the intermediate than adverse group. Our analyses both confirm and challenge prognostic significance of some of the newly added markers.

N-terminal pro-brain natriuretic peptide is a prognostic marker for response to intensive chemotherapy, early death, and overall survival in acute myeloid leukemia.

Patient-related factors are of prognostic importance in acute myeloid leukemia (AML). Likewise, cardiac disorders may limit the tolerance of intensive therapy. Little is known about the prognostic value of N-terminal pro-brain natriuretic peptide (NT-proBNP). We analyzed NT-proBNP levels at diagnosis in 312 AML patients (median age: 61 years; range 17-89 years) treated with 3 + 7-based induction-chemotherapy and consolidation with up to four cycles of intermediate or high-dose ARA-C. NT-proBNP levels were elevated in 199 patients (63.8%), normal (0-125 pg/ml) in 113 (36.2%), and highly elevated (>2000 pg/ml) in 20 patients (6.4%). Median NT-proBNP levels differed significantly among patients with complete remission (153.3pg/ml), no remission (225.9pg/ml), or early death (735.5pg/ml) (p=.002). In multivariate analysis, NT-proBNP, age, and the 2009 European LeukemiaNet (ELN-2009) classification were independent predictors of outcome after induction chemotherapy. Overall survival (OS) differed significantly between patients with normal, moderately elevated, and highly elevated NT-proBNP (p < .001). These differences were observed in all patients and in patients <60 years but not in those ≥60 years. In multivariate analysis, NT-proBNP, age, and ELN-2009 remained independent prognostic variables for OS (p < .01). Together, NT-proBNP is an independent prognostic factor indicating the risk of induction failure, early death, and reduced OS in patients with AML.

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

Phase II Trial of Venetoclax (Ven) in Combination with Azacitidine (AZA) As Maintenance Therapy for High-Risk Acute Leukemia Following Allogeneic Stem Cell Transplantation (SCT)

Introduction: Allogeneic SCT remains the only potentially curative therapy for acute leukemia patients but with inferior outcomes for high-risk patients. Prior data on maintenance therapies, including AZA, have yielded conflicting results on its efficacy to improve outcomes. Considering the clinical efficacy of VEN in acute myeloid and lymphoid leukemia (AML/ALL) with its known tolerability when used with AZA, we thought VEN and AZA might be an attractive maintenance strategy to improve outcomes after SCT. Methods: This is a single center, open label, Phase II clinical trial to assess the safety and efficacy of VEN with AZA as maintenance therapy after SCT. Inclusion criteria was 1) high risk AML or B cell and T cell ALL or mixed phenotype leukemia, 2) absolute neutrophil count >/= 1.0 x 109/L and platelet >/= 30 x 109/L without any support, 3) absence of active graft versus host disease (GvHD) and infection, 4) absence of minimal residual disease at enrollment. Treatment consisted of up to 12 cycles of VEN 100 mg on Days 1-7 with AZA 32 mg/m 2/day IV/SC on Days 1-5 every 28 days. VEN dosing was adjusted for patients on concomitant CYP3A inhibitors or those with severe cytopenias. After the first 11 patients enrolled, due to myelosuppression observed, VEN dose was changed to 50 mg on days 1-7 if patients were on posaconazole. Treatment delays, up to 70 days, were allowed by toxicity. The primary objectives are relapse-free survival (RFS) after initiation of VEN and AZA and the safety and tolerability of the combination. The study has been ongoing. Results: The study enrolled a total of 30 patients (27 AML, 3 ALL). Demographics across all AML patients included mean age 52 years (range: 40-74), 67% males, 15% second SCT, 48% in first complete remission (CR1) at SCT, 41% adverse risk by European Leukemia Net classification. The majority (63%) received a myeloablative intensity conditioning regimen using intravenous busulfan. The three ALL patients were younger with mean age of 35 and all were in CR1 at SCT. The median time to start the maintenance treatment was 70.5 days (range, 42-103). As of the data cutoff date of 13 July 2022, patients completed a median of 4 cycles (range, 1-12) of study treatment with 9 patients (30%) remaining on study treatment. The primary reasons for study treatment discontinuation among 21 patients were complications like myelosuppresssion, infections and GvHD in 11, relapse in 6 and completion of 12 cycles of treatment in 4. The median follow-up time was 8.67 months (95% CI, 7.23 to 13.6).The median RFS and OS were not reached. The estimates of RFS and OS at 1-year were 69.2% (95% CI, 52.1% to 91.8%) and 90.2% (95%CI, 78% to 100%), respectively, after the initiation of VEN and AZA maintenance (Figure 1&2). Assuming a Bayesian Poisson-Gamma Model with a Gamma (1,1) prior; the mean number of grade≥3 treatment related adverse events (AEs) per patient was estimated. The mean number of AEs were 1.87 (range, 0-8) for decreased white blood cell count; 1.68 (range, 0-7) for decreased absolute neutrophil count; 1.06 (range, 0-6) for decreased platelet count; 0.55 (range, 0-6) for anemia; 0.13 (range, 0-1) for pneumonia and 0.06 (range 0-1) for each event of febrile neutropenia, maculopapular rash, respiratory failure and secondary graft failure (GF). The secondary GF was observed in one patient after the 4th cycle of treatment leading to discontinuation of study treatment. No patient died to due to treatment related AEs. Due to frequent and prolonged myelosuppression observed, 9 patients (30%) required dose reduction of VEN; mostly right after the first cycle of treatment (6 of 9 patients). After the protocol amendment for VEN to be given as 50 mg on days 1-7 on posaconazole, the requirement for dose changes decreased though still some patients required lower doses of VEN (as 30 mg on days 1-5) on subsequent cycles. Conclusion: Post-SCT maintenance therapy with VEN/AZA was safe and tolerable with favorable results in patients with high-risk AML and ALL. The majority of reported AEs was related to myelosuppression which is a known complication of VEN. Many patients required dose modification of VEN and treatment delays between cycles, highlighting the importance of monitoring these patients very closely. On the other hand, the observed RFS and OS data were highly encouraging compared to the historical outcomes for this high-risk group of patients although longer follow-up is needed. The study has been ongoing. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Transplant Outcomes for TP53 AML and MDS in a Contemporary Era

Background:TP53 gene mutations are detected in approximately 10%-20% of patients with de novo myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML) and 30%-40% of patients with therapy-related disease. TP53 mutated MDS/AML are associated with a dismal prognosis when treated with intensive chemotherapy alone. Even after allogeneic stem cell transplant (SCT), TP53 mutated MDS and AML patients are shown to have low survival rates. In this single center retrospective analysis, we aimed to investigate the prognostic value of TP53 mutations in patients with MDS/AML that undergo SCT and to identify other variables such as conditioning regimen, use of post-transplant maintenance, donor selection or hematopoietic cell transplantation-specific comorbidity index (HCT-CI) had any impact on the post-transplant outcomes. Methods: Patients with a diagnosis of MDS or AML who received first SCT between January 2013 through April 2022 with available pre-transplant genetic profile obtained from next generation sequencing of genes, and confirmed to have TP53 mutation, were included in the retrospective analysis. Disease risk factors were categorized by the revised International Prognostic Scoring System (R-IPSS) for MDS and European Leukemia Net (ELN)for MDS and AML respectively. When using ELN classification, cytogenetic and molecular data was used as instructed other than TP53 to able to identify different risk groups for SCT outcomes. Primary outcome of interest was risk of relapse-free survival (RFS). MDS and AML patients were analyzed separately. Results: Within the study period, 181 patients (60 MDS and 121 AML) were eligible to be included in this analysis. As shown in the table 1, the study cohort with TP53 mutation was a high risk one; disease risk groups were very-high and high by IPSS-R in 78.4% of MDS, and adverse risk by ELN in 78.5%% of AML patients, respectively. Median age was 66 and 59 in MDS and AML patients and HCT-CI was >2 at SCT in 75% of MDS and 64.5% of AML patients respectively. In MDS patients, median RFS was 8.4 months with 1-year estimate of 44.7% (Figure 1a). By univariate analyses, none of the disease and transplant related characteristics were found to have a prognostic impact on RFS. In AML patients, median RFS was 5.7 months with 1-year estimate of 27.4%. By univariate analyses, as shown in Table 1, adverse risk category by ELN, complete remission without count recovery (CRi/p), advanced disease at transplant and HCT-CI >2 were significant predictors of decreased RFS. The use of post-transplant maintenance was shown to improve RFS. Multivariate regression (MV) in AML patients revealed that adverse risk by ELN (HR=3.6, CI=1.9-6.8, p<0.001), disease status at SCT other than CR1/CR2 (HR=2.1, CI=1.4-3.3, p<0.001) and HCT-CI >2 (HR=1.9, CI=1.9-6.9, p<0.001) were poor risk factors for worse RFS. Maintenance treatment lost its significance to improve RFS with MV (HR=0.76; CI=0.47-1.24, p=0.3). Based on MV, 3 mutually exclusive risk groups for RFS were identified (Figure 1b). The best group included patients with favorable/intermediate risk by ELN, with no more than one other risk factor (CRi/p or advanced disease at SCT or HCT-CI >2) with 1-year RFS of 80%. On the other hand, patients with adverse risk by ELN, transplanted in CRi/p or with advanced disease and had HCT-CI>2 represented a very poor group with 1-year RFS of 0%. Adverse risk ELN patients had slightly better RFS if they had only one other high-risk feature with 1-year estimate of 20%. Overall survival at 1-year in MDS and AML patients were 57.3% and 36.4% respectively. The cause of death was relapse of disease in 65% of MDS and 63% in AML patients. Median time to relapse was 135 days, and incidence of disease relapse was very high as 31.2% at 6 months and 49.5% at 1-year in MDS and 30% at 6 months and 47.9% at 1-year in AML patients. Conclusion: TP53 mutated MDS and AML patients continue to represent one of the worst prognostic groups for outcome expectations after transplant. In our analysis, the conditioning regimen, stem cell source and use of post-transplant maintenance therapies did not lead to improved outcomes. On the other hand, among AML patient, we were able to identify a subgroup with favorable outcomes indicating that other disease related characteristics need to be taken into account while planning transplant in this population. Innovative strategies to improve outcomes are urgently needed for TP53 mutated MDS and AML patient. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Prognostic Impact of the 2022 European Leukemia Net Risk Classification in Patients with Acute Myeloid Leukemia Undergoing Allogeneic Stem Cell Transplantation

Introduction: For most acute myeloid leukemia (AML) patients (pts) an allogeneic stem cell transplantation (HSCT) offers the highest chance of cure. Recently, the European LeukemiaNet (ELN) published updated recommendations on the risk classification in AML pts. In addition to the risk at diagnosis, which is now based on cytogenetics and the mutation status of several genes, a dynamic adjustment according to the measurable residual disease (MRD) status in favorable (fav) and intermediate (int) risk pts at informative time points - such as prior to an allogeneic HSCT - was recommended. A validation of the new ELN2022 risk classification has not been reported. Methods: We retrospectively analyzed 522 AML pts who received an allogeneic HSCT between 2000 and 2021 in first complete remission (CR, 54%), second CR (11%), CR with incomplete count recovery (CRi, 13%), or relapsed/refractory (22%) at our center. Median age at HSCT was 59 (range 16-76) years (y), 53% of pts were younger than 60 y. Conditioning regimens were myeloablative (27%), reduced-intensity (23%) or non-myeloablative (50%). At diagnosis, cytogenetics, and the mutation status of CEBPA, NPM1, and FLT3-ITD were assessed. Using next-generation sequencing we analyzed a panel of 54 recurrently mutated genes in myeloid malignancies (MiSeq platform, Illumina). In pts with material available in remission prior to HSCT, the MRD status based on NPM1mutations, BAALC, MN1, and WT1 expression was evaluated as published previously (Jentzsch 2021). MRD positivity (MRDpos) was defined as positivity of any of the analyzed markers. Median follow up after HSCT was 3.0 y. Results: ELN2022 risk at diagnosis was 22% fav, 26% int, and 52% adverse (adv). Older pts (≥ 60 y at HSCT) had significantly worse ELN2022 genetic risk (P<.001). Comparing the ELN2017 and the new ELN2022, 83% (fav), 70% (int), and 90% (adv) of pts kept their allocation, while 15% and 2% of fav ELN2017 risk pts changed to int and adv ELN2022, 30% of int ELN2017 risk pts changed to adv ELN2022 & 1% and 10% of adv ELN2017 risk pts changed to fav and int ELN2022. Analyzing the c-statistic (area under the curves [AUC]) produced by the ELN2017 and ELN2022 for relapse (AUC2017 = 0.64 vs AUC2022 = 0.64, P=.21) and overall survival (OS) prediction (AUC2017 = 0.60 vsAUC2022 = 0.57, P=.06), the ELN2022 did not perform significantly better. However, the ELN2022 risk at diagnosis impacted cumulative incidence of relapse/progression (CIR, P<.001) and OS (P<.001, Figure 1), which was especially seen in pts < 60 y (CIR P<.001, OFS P<.001), but less so in pts ≥ 60 y at HSCT (CIR P=.002, OS P=.10). At diagnosis, outcomes did not differ significantly with respect to the specific genetic abnormality defining the ELN2022 fav or the ELN2022 int risk. Also a high or low FLT3-ITD allelic ratio (0.5 cut) within the ELN2022 int risk did not result in distinct outcomes (CIR P=.13, OS P=.30). In contrast, within pts harboring adv ELN2022 risk, CIR (P=.05) and OS (P<.001) significantly differed according to the presence of specific genetic abnormalities; i.e. a complex karyotype (at 3 y: CIR 59%, OS 30%), other adverse cytogenetic aberrations (at 3 y: CIR 50%, OS 54%), adverse-risk gene mutation (i.e.ASXL1, RUNX1, or TP53, at 3 y: CIR 47%, OS 58%), or secondary AML-like gene mutations (at 3 y: CIR 30%, OS 73%). When we adjusted fav and int risk pts according to the MRD status at HSCT as proposed by the ELN2022 recommendations, 49% of fav risk pts at diagnosis had persisting MRD and were reclassified as int risk at HSCT while 53% of int risk pts at diagnosis were MRD negative and reclassified as fav risk at HSCT. Outcomes of MRD-adjusted fav risk pts improved (at 3 y: CIR 12%, OS 75%), while that of MRD-adjusted int risk pts (at 3 y: CIR 53%, OS 49%) was similar to that of adv risk pts transplanted in morphologic CR/CRi (at 3 y: CIR 47%, OS 54%). Conclusion: In the context of an allogeneic HSCT, the proposed risk assessments by the ELN2022 significantly impacted outcomes at diagnosis as well as after adjustment according to MRD status prior to HSCT of AML pts. However, it did not perform significantly better than the previous ELN2017 risk stratification. The FLT3-ITD allelic ratio did not significantly impacted outcomes within the ELN2022 int risk, justifying the removal from the risk stratification. Noteworthy, in pts receiving allogeneic HSCT, secondary AML-like gene mutations did not associate with adverse outcomes when no other adverse-risk characteristics were present. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Real-Life Comparative Analysis of Prognostic Risk Classification According to ELN 2010, 2017 and 2022 in AML Patients

Background Prognostic risk stratification is crucial to individualize treatment in AML patients. The 2010 European Leukemia Net (ELN) classification grouped patients into 4 risk categories based on genetic alterations, which were redefinedinto 3 prognostic groups in 2017 taking into account new molecular data (TP53, RUNX1 and ASXL1). Recently, ELN has proposed a new update considering additional prognostic mutations (such as SF3B1, SRSF2 and U2AF1)and removing ratio for FLT3-ITD. These ELN 2022 recommendations have not been validated yet in large cohorts of AML patients in real life. Aims 1. Analyze the mutational landscape detected by Next Generation Sequencing (NGS) in consecutive real-life AML patients 2. Analyze whether the application of ELN 2022 risk model improves prognostic risk stratification compared to ELN 2010and 2017 and Medical Research Council (MRC). Methods We included 112 adult AML patients diagnosed in our center between June 2017 and December 2021 (Table 1) and who were studied at diagnostic using the Spanish PLATAFOLMA PETHEMA. The prognostic risk was established according to MRC, ELN 2010, ELN 2017 and ELN 2022 classification. NPM1 and FLT3-ITD were determined by melting curve analysis and standard PCR-EC technique according to Thiede et al (Blood 2002) in ABI 3130 Analyzer (Thermofisher). For NGS, the commercial panel Myeloid SolutionTM (Sophia Genetics) KAPA Kit amplification libraries and sequencing on ILUMINA Myseq platform were used. Variant analysis was performed using DDM software (Sophia Genetics). Results The majority of patients (97.1%) had at least one mutation at diagnosis detected by NGS. The median number of mutations was 2.4 (0-6). Grouped by functional genes, the most frequent were those related to DNA methylation (44.6 %) and signaling/kinase pathways (37.5%). The most prevalent were FLT3 (29 %), IDH1/IDH2 (27%) and TP53 (19.6%) followed by NPM1 and RUNX1 (17%). Patients older than 60 years, presented higher percentage of unfavorable ASXL1 (18.6%), RUNX1 (20%) and TP53 (25.7%) mutations with respect to younger (4.8%, 11.9% and 9.5%) being these differences statistically significant in ASXL1 and TP53 (P=0.044 and P=0.047, respectively). NPM1 (28.6%) and FLT3 (40.5%) mutations were significantly more frequent in younger patients (P=0.017 and P=0.013, respectively), than in >60 years (10% and 17.1%, respectively). Re-stratifying according to ELN2022, 32.4% of patients categorized within the intermediate risk group according to ELN 2017 change to adverse prognostic group and 13.2% in adverse risk group change to intermediate group due to the lack of impact of ratio for FLT3-ITD. In the global series, the overall survival (OS) analysis shows statistically significant differences taking into account either ELN 2022, ELN 2017 or ELN 2010 and MRC (P=0.001,P=0.010, P=0.049 and P=0.012, respectively) (Figure 1). However, the greater differences between intermediate and unfavorable groups are found according to ELN 2022 compared to other classifications, and are also confirmed in patients receiving intensive treatment (P=0.021).Remarkably, patients receiving allotransplantation reverse adverse prognosis and enhance survival similar to intermediate group. In our series, patients harboring mutations in signaling pathways genes (including FLT3) show better OS than those lacking, reaching statistical significance in allo-HSCT patients (P=0.037). Summary/Conclusion 1. Our results validate the prognostic significance of the ELN2022 classification in real life, for the overall series and for candidates to intensive treatment. 2.ELN 2022 establishes greater survival differences between the unfavorable and intermediate group than ELN 2017or prior classifications. However, patients in adverse group undergoing allo-HSCT improve OS similar to intermediate group 3. FLT3 mutated allo-HSCT patients showed a strikingly low risk of relapse, partly due to the treatment with FLT3 inhibitors. 4. New studies including larger number of patients are needed to confirm our results. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal