A real-world analysis of clinical outcomes in AML with myelodysplasia-related changes: a comparison of ICC and WHO-HAEM5 criteria.

ABSTRACT: The proposed fifth edition of the World Health Organization classification of hematolymphoid tumors (WHO-HAEM5) and International Consensus Classification (ICC) provide different definitions of acute myeloid leukemia with myelodysplasia-related genetics (AML-MR). We conducted a retrospective study which included a cohort of 432 patients, with 354 patients fulfilling WHO-HAEM5 criteria for WHO-AML-MR or 276 patients fulfilling ICC criteria for ICC-AML-MR by gene mutation or cytogenetics (ICC-AML-MR-M/CG). The clinicopathological features were largely similar, irrespective of the classification used, except for higher rates of complex karyotype, monosomy 17, TP53 mutations, and fewer RUNX1 mutations in the WHO-AML-MR group. TP53 mutations were associated with distinct clinicopathological features and dismal outcomes (hazard ratio [HR], 2.98; P < .001). ICC-AML-MR-M/CG group had superior outcome compared with the WHO-AML-MR group (HR, 0.80, P = .032), largely in part due to defining TP53 mutated AML as a standalone entity. In the intensively-treated group, WHO-AML-MR had significantly worse outcomes than AML by differentiation (HR, 1.97; P = .024). Based on ICC criteria, ICC-AML-MR-M/CG had more inferior outcomes compared to AML not otherwise specified (HR, 2.11; P = .048 and HR, 2.55; P = .028; respectively). Furthermore, changing the order of genetic abnormalities defining AML-MR (ie, by gene mutations or cytogenetics) did not significantly affect clinical outcomes. ICC-AML-MR-M/CG showed similar outcomes regardless of the order of assignment. We propose to harmonize the 2 classifications by excluding TP53 mutations from WHO-HAEM5 defined AML-MR group and combining AML-MR defined by gene mutations and cytogenetics to form a unified group.

AML with CEBPA mutations: A comparison of ICC and WHO-HAEM5 criteria in patients with 20% or more blasts.

AML with CEBPA mutation and AML with in-frame bZIP CEBPA mutations define favorable-risk disease entities in the proposed 5th edition of the World Health Organization Classification (WHO-HAEM5) and the International Consensus Classification (ICC), respectively. However, the impact of these new classifications on clinical practice remains unclear. We sought to assess the differences between the ICC and WHO-HAEM5 for AML with CEBPA mutation. 741 AML patients were retrospectively analyzed. Cox proportional-hazard regression was used to identify factors predictive of outcome. A validation cohort from the UK-NCRI clinical trials was used to confirm our findings. 81 (11%) AML patients had CEBPA mutations. 39 (48%) patients met WHO-HAEM5 criteria for AML with CEBPA mutation, among which 30 (77%) had biallelic CEBPA mutations and 9 (23%) had a single bZIP mutation. Among the 39 patients who met WHO-HAEM5 criteria, 25 (64%) also met ICC criteria. Compared to patients only meeting WHO-HAEM5 criteria, patients with in-frame bZIP CEBPA mutations (ie. meeting both WHO-HAEM5 and ICC criteria) were younger, had higher bone marrow blast percentages and CEBPA mutation burden, infrequently harboured 2022 ELN high-risk genetic features and co-mutations in other genes, and had superior outcomes. The associations in clinicopathological features and outcomes between the CEBPA-mutated groups were validated in the UK-NCRI cohort. Our study indicates that in-frame bZIP CEBPA mutations are the critical molecular aberrations associated with favorable outcomes in AML patients treated with curative intent chemotherapy. Compared to WHO-HAEM5, the ICC identifies a more homogenous group of CEBPA-mutated AML patients with favorable outcomes.

TP53 Mutations in AML Patients Are Associated with Dismal Clinical Outcome Irrespective of Frontline Induction Regimen and Allogeneic Hematopoietic Cell Transplantation.

TP53 mutations are associated with extremely poor outcomes in acute myeloid leukemia (AML). The outcomes of patients with TP53-mutated (TP53MUT) AML after different frontline treatment modalities are not well established. Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative procedure for AML; however, long-term outcomes among patients with TP53MUT AML after allo-HCT are dismal, and the benefit of allo-HCT remains controversial. We sought to evaluate the outcomes of patients with TP53MUT AML after treatment with different frontline induction therapies and allo-HCT. A total of 113 patients with TP53MUT AML were retrospectively evaluated. Patients with TP53MUT AML who received intensive or azacitidine-venetoclax induction had higher complete remission rates compared to patients treated with other hypomethylating-agent-based induction regimens. However, OS and EFS were not significantly different among the induction regimen groups. Allo-HCT was associated with improved OS and EFS among patients with TP53MUT AML; however, allo-HCT was not significantly associated with improved OS or EFS in time-dependent or landmark analysis. While the outcomes of all patients were generally poor irrespective of therapeutic strategy, transplanted patients with lower TP53MUT variant allele frequency (VAF) at the time of diagnosis had superior outcomes compared to transplanted patients with higher TP53 VAF. Our study provides further evidence that the current standards of care for AML confer limited therapeutic benefit to patients with TP53 mutations.

Molecular genetic characterization of Philadelphia chromosome-positive acute myeloid leukemia.

BACKGROUND: Philadelphia chromosome-positive acute myeloid leukemia (Ph+ AML) is a provisional disease entity in the 2016 WHO classification, while its genetic profile of Ph+ AML remains poorly defined. In addition, the differentiating features of Ph+ AML and chronic myeloid leukemia in myeloid blast crisis (CML-MBC) remain controversial. METHODS: We conducted a retrospective study of 15 Ph+ AML patients to compare their clinical and laboratory profiles with 27 CML-MBC patients. RESULTS: Compared to CML-MBC, Ph+ AML patients presented with significantly higher peripheral WBC count and bone marrow blast percentage. The immunophenotypic profiles were largely similar between Ph+ AML and CML-MBC, except for CD4 expression, which was significantly enriched in CML-MBC. Ph+ AML patients less frequently harboured co-occurring additional cytogenetic abnormalities (ACA) compared to CML-MBC, and trisomy 19 (23%) and IDH1/2 (46%) were the most common ACA and mutated genes in Ph+ AML, respectively. Overall survival (OS) did not significantly differ between Ph+ AML and CML-MBC. Ph+ AML without CML-like features appeared to have a better outcome compared to Ph+ AML with CML-like features; ACA in Ph+ AML may confer an even worse prognosis. CONCLUSIONS: Our results indicate that patients with Ph+ AML share similar genetic profiles and clinical outcomes with those with CML-MBC, thus should be classified as a high-risk entity.

Molecular characterization of AML-MRC reveals TP53 mutation as an adverse prognostic factor irrespective of MRC-defining criteria, TP53 allelic state, or TP53 variant allele frequency.

BACKGROUND: Acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) generally confers poor prognosis, however, patient outcomes are heterogeneous. The impact of TP53 allelic state and variant allele frequency (VAF) in AML-MRC remains poorly defined. METHODS: We retrospectively evaluated 266 AML-MRC patients who had NGS testing at our institution from 2014 to 2020 and analyzed their clinical outcomes based on clinicopathological features. RESULTS: TP53 mutations were associated with cytogenetic abnormalities in 5q, 7q, 17p, and complex karyotype. Prognostic evaluation of TP53MUT AML-MRC revealed no difference in outcome between TP53 double/multi-hit state and single-hit state. Patients with high TP53MUT variant allele frequency (VAF) had inferior outcomes compared to patients with low TP53MUT VAF. When compared to TP53WT patients, TP53MUT patients had inferior outcomes regardless of MRC-defining criteria, TP53 allelic state, or VAF. TP53 mutations and elevated serum LDH were independent predictors for inferior OS and EFS, while PHF6 mutations and transplantation were independent predictors for favorable OS and EFS. NRAS mutation was an independent predictor for favorable EFS. CONCLUSIONS: Our study suggests that TP53MUT AML-MRC defines a very-high-risk subentity of AML in which novel therapies should be explored.

NPM1-mutated AML-MRC diagnosed on the basis of history of MDS or MDS/MPN frequently harbours secondary-type mutations and confers inferior outcome compared to AML with mutated NPM1.

BACKGROUND: Acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) is a prognostically diverse disease. Owing to its favourable prognosis, AML-MRC with mutated NPM1 (NPM1MUT) diagnosed on the basis of multi-lineage dysplasia has been reclassified into "AML with mutated NPM1". However, it remains unclear if NPM1MUT AML with antecedent MDS or MDS/MPN (AML-MRC-H) should also be reclassified into this subentity. The mutational landscape of NPM1MUT AML-MRC-H remains poorly defined. METHODS: The clinicopathological features, molecular profiles and outcomes of 241 AML-MRC-H and 332 normal karyotype (NK)-AML with mutated NPM1 patients were retrospectively analyzed. Fisher's exact test, chi-square test and Wilcoxon rank-sum test were used to compare clinicopathological and molecular features. Overall survival and event-free survival were compared using the log-rank test. Multivariable survival analysis was performed using Cox proportional hazards regression. RESULTS: 33 (14%) AML-MRC-H patients had an NPM1 mutation. By NGS, NPM1MUT AML-MRC-H patients had a significantly higher frequency of secondary-type mutations in U2AF1 and ASXL1 compared to NK-AML with mutated NPM1. NPM1MUT AML-MRC-H was significantly associated with inferior outcomes compared to NK-AML with mutated NPM1. Bone marrow transplantation had a favourable prognostic impact in NPM1MUT AML-MRC-H. CONCLUSIONS: NPM1MUT AML-MRC-H has inferior prognosis compared to NK-AML with mutated NPM1, likely due to the higher frequency of secondary-type mutations, and thus should still be included in the high-risk subentity of AML-MRC. NPM1MUT AML-MRC patients may benefit from bone marrow transplantation.

Targeting an MDM2/MYC Axis to Overcome Drug Resistance in Multiple Myeloma.

BACKGROUND: MDM2 is elevated in multiple myeloma (MM). Although traditionally, MDM2 negatively regulates p53, a growing body of research suggests that MDM2 plays several p53-independent roles in cancer pathogenesis as a regulator of oncogene mRNA stability and translation. Yet, the molecular mechanisms underlying MDM2 overexpression and its role in drug resistance in MM remain undefined. METHODS: Both myeloma cell lines and primary MM samples were employed. Cell viability, cell cycle and apoptosis assays, siRNA transfection, quantitative real-time PCR, immunoblotting, co-immunoprecipitation (Co-IP), chromatin immunoprecipitation (ChIP), soft agar colony formation and migration assay, pulse-chase assay, UV cross-linking, gel-shift assay, RNA-protein binding assays, MEME-analysis for discovering c-Myc DNA binding motifs studies, reporter gene constructs procedure, gene transfection and reporter assay, MM xenograft mouse model studies, and statistical analysis were applied in this study. RESULTS: We show that MDM2 is associated with poor prognosis. Importantly, its upregulation in primary MM samples and human myeloma cell lines (HMCLs) drives drug resistance. Inhibition of MDM2 by RNAi, or by the MDM2/XIAP dual inhibitor MX69, significantly enhanced the sensitivity of resistant HMCLs and primary MM samples to bortezomib and other anti-myeloma drugs, demonstrating that MDM2 can modulate drug response. MDM2 inhibition resulted in a remarkable suppression of relapsed MM cell growth, colony formation, migration and induction of apoptosis through p53-dependent and -independent pathways. Mechanistically, MDM2 was found to reciprocally regulate c-Myc in MM; MDM2 binds to AREs on c-Myc 3'UTR to increase c-Myc mRNA stability and translation, while MDM2 is a direct transcriptional target of c-Myc. MDM2 inhibition rendered c-Myc mRNA unstable, and reduced c-Myc protein expression in MM cells. Importantly, in vivo delivery of MX69 in combination with bortezomib led to significant regression of tumors and prolonged survival in an MM xenograft model. CONCLUSION: Our findings provide a rationale for the therapeutic targeting of MDM2/c-Myc axis to improve clinical outcome of patients with refractory/relapsed MM.